Blood Test Results: Your Guide to Understanding the Numbers

AnTabolic73

Well-known Member
www.newportnaturalhealth.com/2012/08/a-guide-to-understanding-blood-tests/

I'm awaiting some bloods I just took, so I was looking to brush up on some of the tests. I ran into this site...


Chemistry Panel (or Metabolic Panel)
ALT (alanine aminotransferase)
Healthy range: 8 to 37 IU/L
This test looks at levels of the liver enzyme ALT. When all’s well with your liver, your score on this test should be within range. Anything higher may indicate liver damage.

Albumin
Healthy range: 3.9 to 5.0 g/dL
A protein made by the liver, albumin levels can be an indicator of liver or kidney problems.

A/G ratio (albumin/globulin ratio) or total protein test
Healthy ratio: a bit over 1, favoring albumin
There are two types of protein your blood — albumin (see above) and globulin. The A/G ratio test compares levels of these proteins with one another. Elevated protein levels could indicate a health condition in need of attention.

Alkaline phosphatase
Healthy range: 44 to 147 IU/L
This enzyme is involved in both liver and bone, so elevations may indicate problems with the liver or bone-related disease.

AST (aspartate aminotransferase)
Healthy range: 10 to 34 IU/L
This enzyme is found in heart and liver tissue, so elevations suggest problems may be occurring in one or both of those areas.

Bilirubin
Healthy range: 0.1 to 1.9 mg/dL
This provides information about liver and kidney functions, problems in bile ducts, and anemia.

BUN (blood urea nitrogen)
Healthy range: 10 to 20 mg/dL
This is another measure of kidney and liver functions. High values may indicate a problem with kidney function. A number of medications and a diet high in protein can also raise BUN levels.

BUN/creatinine ratio
Healthy ratio of BUN to creatinine: 10:1 to 20:1 (men and older individuals may be a bit higher)
This test shows if kidneys are eliminating waste properly. High levels of creatinine, a by-product of muscle contractions, are excreted through the kidneys and suggest reduced kidney function.

Calcium
Healthy range: 9.0 to 10.5 mg/dL (the elderly typically score a bit lower)
Too much calcium in the bloodstream could indicate kidney problems; overly active thyroid or parathyroid glands; certain types of cancer, including lymphoma; problems with the pancreas; or a deficiency of vitamin D.

Chloride
Healthy range: 98 to 106 mEq/L
This mineral is often measured as part of an electrolyte panel. A high-salt diet and/or certain medications are often responsible for elevations in chloride. Excess chloride may indicate an overly acidic environment in the body. It also could be a red flag for dehydration, multiple myeloma, kidney disorders, or adrenal gland dysfunction.

Creatinine
Healthy range: 0.5 to 1.1 mg/dL for women; 0.6 to 1.2 mg/dL for men (the elderly may be slightly lower)
The kidneys process this waste product, so elevations could indicate a problem with kidney function.

Fasting glucose (blood sugar)
Healthy range: 70 to 99 mg/dL for the average adult (the elderly tend to score higher even when they are healthy)
Blood sugar levels can be affected by food or beverages you have ingested recently, your current stress levels, medications you may be taking, and the time of day. The fasting blood sugar test is done after at least 6 hours without food or drink other than water.

Phosphorus
Healthy range: 2.4 to 4.1 mg/dL
Phosphorus plays an important role in bone health and is related to calcium levels. Too much phosphorus could indicate a problem with kidneys or the parathyroid gland. Alcohol abuse, long-term antacid use, excessive intake of diuretics or vitamin D, and malnutrition can also elevate phosphorus levels.

Potassium
Healthy range: 3.7 to 5.2 mEq/L
This mineral is essential for relaying nerve impulses, maintaining proper muscle functions, and regulating heartbeats. Diuretics, drugs that are often taken for high blood pressure, can cause low levels of potassium.

Sodium
Healthy range: 135 to 145 mEq/L
Another member of the electrolyte family, the mineral sodium helps your body balance water levels and helps with nerve impulses and muscle contractions. Irregularities in sodium levels may indicate dehydration; disorders of the adrenal glands; excessive intake of salt, corticosteroids, or pain-relieving medications; or problems with the liver or kidneys.


Lipid Panel (or Lipid Profile)
The lipid panel is a collection of tests measuring different types of cholesterol and triglycerides (fats) in your bloodstream.

Total cholesterol
General rules (best to worst):



Healthy Below 200 mg/dL (below 5.18 mmol/L)


Borderline high 200 to 239 mg/dL (5.2 to 6.2 mmol/L)


High Above 240 mg/dL (above 6.2 mmol/L)
This test measures combined levels of both LDL (bad) and HDL (good) cholesterol. The test may be done simply to record an individual’s cholesterol levels or for comparison purposes (e.g., to determine if cholesterol-lowering medications or nutrients are working).

Triglycerides
Healthy range: 40 to 160 mg/dL
These fats are found in the bloodstream and may contribute to heart disease and other health problems.

HDL (Good) cholesterol
General rules:



Best Above 60 mg/dL


Good 50 to 60 mg/dL


Poor Below 40 mg/dL for men; below 50 mg/dL for women
Also known as good cholesterol, HDL (high-density lipoprotein) protects against heart disease. Low scores are risk factors for heart disease.
LDL (Bad) cholesterol
General rules (best to worst):



Optimal Below 100 mg/dL


Near optimal 100 to 129 mg/dL


Borderline high 130 to 159 mg/dL


High 160 to 189 mg/dL


Very high Above 189 mg/dL
Also known as bad cholesterol, LDL (low-density lipoprotein) is the substance that clogs arteries and is linked to heart disease.

Total cholesterol/HDL ratio
American Heart Association guidelines:



Optimal Ratio of 3.5 to 1


Healthy Ratio of 5 to 1 or lower
This ratio is another way of checking your risk of heart disease. It is determined by dividing your HDL cholesterol level into total cholesterol. But don’t worry about the math — the lab normally does the calculation, so your doctor will simply tell you what the ratio is.


Complete Blood Count (CBC)
The CBC test examines cellular elements in the blood, including red blood cells, various white blood cells, and platelets. Here is a list of the components that are normally measured, along with typical values. If your doctor says you’re fine but your tests results are somewhat different from the range shown here, don’t be alarmed. Some labs interpret test results a bit differently from others, so don’t consider these figures absolutes.

WBC (white blood cell) leukocyte count
Normal range: 4,300 to 10,800 cmm
White blood cells help fight infections, so a high white blood cell count could be helpful for identifying infections. It may also indicate leukemia, which can cause an increase in the number of white blood cells. On the other hand, too few white blood cells could be caused by certain medications or health disorders.

WBC (white blood cell) differential count
Normal range:



Neutrophils 40% to 60% of the total


Lymphocytes 20% to 40%


Monocytes 2% to 8%


Eosinophils 1% to 4%


Basophils 0.5% to 1%
This test measures the numbers, shapes, and sizes of various types of white blood cells listed above. The WBC differential count also shows if the numbers of different cells are in proper proportion to each other. Irregularities in this test could signal an infection, inflammation, autoimmune disorders, anemia, or other health concerns.

RBC (red blood cell) erythrocyte count
Normal range: 4.2 to 5.9 million cmm
We have millions of red blood cells in our bodies, and this test measures the number of RBCs in a specific amount of blood. It helps us determine the total number of RBCs and gives us an idea of their lifespan, but it does not indicate where problems originate. So if there are irregularities, other tests will be required.

Hematocrit (Hct)
Normal range: 45% to 52% for men; 37% to 48% for women
Useful for diagnosing anemia, this test determines how much of the total blood volume in the body consists of red blood cells.

Hemoglobin (Hgb)
Normal range: 13 to 18 g/dL for men; 12 to 16 g/dL for women
Red blood cells contain hemoglobin, which makes blood bright red. More importantly, hemoglobin delivers oxygen from the lungs to the entire body; then it returns to the lungs with carbon dioxide, which we exhale. Healthy hemoglobin levels vary by gender. Low levels of hemoglobin may indicate anemia.

Mean corpuscular volume (MCV)
Normal range: 80 to 100 femtoliters
This test measures the average volume of red blood cells, or the average amount of space each red blood cell fills. Irregularities could indicate anemia and/or chronic fatigue syndrome.

Mean corpuscular hemoglobin (MCH)
Normal range: 27 to 32 picograms
This test measures the average amount of hemoglobin in the typical red blood cell. Results that are too high could signal anemia, while those too low may indicate a nutritional deficiency.

Mean corpuscular hemoglobin concentration (MCHC)
Normal range: 28% to 36%
The MCHC test reports the average concentration of hemoglobin in a specific amount of red blood cells. Here again, we are looking for indications of anemia if the count is low, or possible nutritional deficiencies if it’s high.

Red cell distribution width (RDW or RCDW)
Normal range: 11% to 15%
With this test, we get an idea of the shape and size of red blood cells. In this case, “width” refers to a measurement of distribution, not the size of the cells. Liver disease, anemia, nutritional deficiencies, and a number of health conditions could cause high or low RDW results.

Platelet count
Normal range: 150,000 to 400,000 mL
Platelets are small portions of cells involved in blood clotting. Too many or too few platelets can affect clotting in different ways. The number of platelets may also indicate a health condition.

Mean Platelet Volume (MPV)
Normal range: 7.5 to 11.5 femtoliters
This test measures and calculates the average size of platelets. Higher MPVs mean the platelets are larger, which could put an individual at risk for a heart attack or stroke. Lower MPVs indicate smaller platelets, meaning the person is at risk for a bleeding disorder.

Additional Recommended Tests
Thyroid
While not part of the standard blood panel, I often order thyroid tests for my patients, especially if they report fatigue and weight gain, or weight loss and feelings of nervousness or hyperactivity. Some physicians dismiss borderline low or high tests, but I’ve found that these can be very helpful for identifying problems with the thyroid gland. Here are the ranges I look for in thyroid tests:

Test Normal Range


Thyroid-stimulating hormone (TSH) 0.3 to 3


Total T4 (total thyroxine) 4.5 to 12.5


Free T4 (free thyroxine) 0.7 to 2.0


Total T3 (total triiodothyronine) 80 to 220


Free T3 (free triiodothyronine) 2.3 to 4.2
If your test shows you are below the minimum numbers, you may be suffering from hypothyroidism, or low thyroid. If your scores are above the normal range, you may have an overly active thyroid, or hyperthyroidism. In either case, your physician can advise you on appropriate medication.
 
labtestsonline.org/understanding/analytes/fsh/tab/test/


FSH
How is it used?
The test for follicle-stimulating hormone (FSH), a hormone associated with reproduction and the development of eggs in women and sperm in men, has several uses.

In both women and men, the test may be used with other hormone tests such as luteinizing hormone (LH), testosterone, estradiol, and/or progesterone to help:

  • Determine the cause of infertility
  • Diagnose conditions associated with dysfunction of the ovaries or testicles
  • Aid in the diagnosis of pituitary or hypothalamus disorders, which can affect FSH production
In women, FSH levels are also useful in:

  • The investigation of menstrual irregularities
  • Predicting onset or confirmation of menopause
In men, FSH levels are used to help determine the reason for a low sperm count.

In children, FSH and LH are used to help diagnose delayed or precocious (early) puberty. Irregular timing of puberty may be an indication of a more serious problem involving the hypothalamus, the pituitary gland, the ovaries or testicles, or other systems. The measurement of LH and FSH may differentiate between benign symptoms and true disease. Once it is established that symptoms are a result of true disease, further testing can be done to discern the underlying cause.

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menopause.

For a man, the test may be ordered when his partner cannot get pregnant, when he has a low sperm count, or when he has low muscle mass or decreased sex drive, for example.

In both women and men, testing may be ordered when a health practitioner suspects that a pituitary disorder is present. A pituitary disorder can affect the production of several different hormones, so there may be signs and symptoms in addition to some of those listed above. They can include fatigue, weakness, unexplained weight loss, and decreased appetite to name a few.

In children, FSH and LH may be ordered when a boy or girl does not appear to be entering puberty at an appropriate age (either too late or too soon). Signs of puberty may include:

  • Breast enlargement in girls
  • Growth of pubic hair
  • Growth of the testicles and penis in boys
  • Beginning of menstruation in girls
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Results of an FSH test are typically considered with results of other hormone tests, such as LH , estrogens, and/or testosterone.

As part of an infertility workup, a high or low FSH is not diagnostic but provides a piece of information on what may be the cause. For example, a hormone imbalance may affect a woman's menstrual cycle and/or ovulation. A health practitioner will consider all the information from the workup to establish a diagnosis. See the Infertility article for more on this.

In Women

FSH and LH levels can help to differentiate between primary ovarian failure (failure of the ovaries themselves) and secondary ovarian failure (failure of the ovaries due to disorders of either the pituitary or the hypothalamus).

High levels of FSH and LH are consistent with primary ovarian failure. Some causes of primary ovarian failure are listed below.

Developmental defects:

  • Failure to develop ovaries (ovarian agenesis)
  • Chromosomal abnormality, such as Turner syndrome
  • Defect in the steroid production by the ovaries, such as 17 alpha hydroxylase deficiency
Premature failure of the ovaries due to:

Chronic failure to ovulate (https://labtestsonline.org/glossary/anovulation/) due to:

When a woman enters menopause and her ovaries stop working, FSH levels will rise.

Low levels of FSH and LH are consistent with secondary ovarian failure due to a pituitary disorder or hypothalamic problem. Low FSH serum levels have been associated with increased risk of ovarian cancer.

In Men

High FSH levels are due to primary testicular failure. This can be the result of developmental defects in testicular growth or to testicular injury, as indicated below.

Developmental defects:

  • Failure to develop gonads (gonadal agenesis)
  • Chromosomal abnormality, such as Klinefelter syndrome
Testicular failure:

  • Viral infection (mumps)
  • Trauma
  • Radiation exposure
  • Chemotherapy
  • Autoimmune disease
  • Germ cell tumor
Low levels are consistent with pituitary or hypothalamic disorders. See the article on Pituitary Disorders for more information.

In Children

High levels of FSH and LH with the development of secondary sexual characteristics at an unusually young age are an indication of precocious puberty. This is much more common in girls than in boys. This premature development is usually due to a problem with the central nervous system and can have a few different underlying causes. Examples include:

  • Central nervous system tumor
  • Brain injury, trauma
  • Inflammation within the central nervous system (e.g. meningitis, encephalitis)
  • Brain surgery
Normal prepubescent levels of LH and FSH in children exhibiting some signs of pubertal changes may indicate a condition call "precocious pseudopuberty." The signs and symptoms are brought on by elevated levels of the hormones estrogen or testosterone. This may be caused by:

  • Hormone-secreting tumors
  • Adrenal gland tumors
  • Ovarian tumors or https://labtestsonline.org/glossary/cyst/
  • Testicular tumors
Normal FSH and LH levels with a few signs of puberty can also be a benign form of precocious puberty with no underlying or discernable cause or may just be a normal variation of puberty.

In delayed puberty, LH and FSH levels can be normal or below what is expected for a youth within this age range. Some of the causes for delayed puberty can include:

  • Dysfunction of the ovaries or testicles
  • Hormone deficiency
  • Turner syndrome
  • Klinefelter syndrome
  • Chronic infections
  • Cancer
  • Eating disorder (anorexia nervosa)
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Is there anything else I should know?
FSH results can be increased with use of certain drugs, including cimetidine, clomiphene, digitalis, and levodopa. FSH results can be decreased with oral contraceptives, phenothiazines, and hormone treatments. FSH will also be low when women are pregnant. A recent nuclear medicine scan may interfere with results of the FSH test if it is measured by a radioimmunoassay, which is seldom used any more.
 
labtestsonline.org/understanding/analytes/lh/tab/test/


LH

How is it used?

The test for luteinizing hormone (LH), a hormone associated with reproduction and the stimulation of the release of an egg from the ovary (ovulation) in women and testosterone production in men, has several uses.

In both women and men, LH is often used in conjunction with other tests (FSH, testosterone, estradiol and progesterone):

  • In the workup of infertility
  • To aid in the diagnosis of pituitary disorders that can affect LH production
  • To help diagnose conditions associated with dysfunction of the ovaries or testicles
In women, LH levels are useful:

  • In the investigation of menstrual irregularities
  • To evaluate LH levels during the menstrual cycle; multiple urine LH tests may be ordered for this purpose. These LH "spot tests" can be performed at home and used to detect the surge in LH that indicates that ovulation will occur in the next 1-2 days. The tests can help determine when a woman is likely to be the most fertile.
In children, FSH and LH are used to diagnose delayed and precocious (early) puberty. Irregular timing of puberty may be an indication of a more serious problem involving the hypothalamus, the pituitary gland, the ovaries or testicles, or other systems. The measurement of LH and FSH may differentiate between benign symptoms and true disease. Once it is established that symptoms are a result of true disease, further testing can be done to discern the underlying cause.

In persons with evidence of poor ovarian or testicular function, LH is sometimes measured in response to administration of gonadotropin releasing hormone (GnRH) to distinguish between disorders involving the hypothalamus or pituitary gland. GnRH is the hormone produced by the hypothalamus that stimulates the pituitary to release LH and FSH. For this test, a baseline blood sample is drawn and then the person is given an injection of GnRH. Subsequent blood samples are drawn at specified times and the level of LH is measured. This test can help differentiate between a disorder of the pituitary (secondary), when LH will not respond to GnRH, or hypothalamus (tertiary), when LH responds to GnRH. It is also often helpful in the evaluation of precocious or delayed puberty.

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FSH) tests may be ordered when:

  • A woman is having difficulty getting pregnant or has irregular or an absence of menstrual periods
  • When it is suspected that a women has entered menopause and her menstrual cycle has stopped or become irregular
  • When a man's partner cannot get pregnant, when he has a low testosterone level, or when he has low muscle mass or decreased sex drive, for example.
  • When a health practitioner suspects that a pituitary disorder is present; a pituitary disorder can affect the production of several different hormones so there may be signs and symptoms in addition to infertility that can include fatigue, weakness, unexplained weight loss, and decreased appetite to name a few.
In children, LH and FSH may be ordered when a boy or girl does not appear to be entering puberty at an appropriate age (either too late or too soon). Signs of puberty may include:

  • Breast enlargement in girls
  • Growth of pubic hair
  • Growth of testicles and penis in boys
  • Beginning of menstruation in girls
^ Back to top



In Women

LH and FSH levels can help to differentiate between primary ovarian failure (failure of the ovaries themselves or lack of ovarian development) and secondary ovarian failure (failure of the ovaries due to disorders of either the pituitary or the hypothalamus).

Increased levels of LH and FSH are seen in primary ovarian failure. Some causes of primary ovarian failure are listed below.

Developmental defects:

  • Failure to develop ovaries (ovarian agenesis)
  • Chromosomal abnormality, such as Turner syndrome
  • Defect in steroid production by the ovaries, such as 17 alpha hydroxylase deficiency
Premature ovarian failure due to:

Chronic failure to ovulate (https://labtestsonline.org/glossary/anovulation/) due to:

In women who are trying to become pregnant, multiple LH tests can be used to detect the surge that precedes ovulation. An LH surge indicates that ovulation has occurred.

During menopause, a woman's ovaries cease to function; thus LH levels will rise.

Low levels of LH and FSH are seen in secondary ovarian failure and indicate a problem with the pituitary or hypothalamus. See the article on Pituitary Disorders for more information.

In Men

High LH levels may indicate primary testicular failure. This can be due to developmental defects in testicular growth or to testicular injury, as described below.

Developmental defects:

  • Failure to develop gonads (gonadal agenesis)
  • Chromosomal abnormality, such as Klinefelter syndrome
Testicular failure:

  • Viral infection (mumps)
  • Trauma
  • Exposure to radiation
  • Chemotherapy
  • Autoimmune disease
  • Germ cell tumor
Low levels of LH and FSH are seen in secondary failure of the testicles and indicate a problem with the pituitary or hypothalamus. See the article on Pituitary Disorders for more information.

In Both Men and Women

LH response to GnRH can help differentiate between secondary dysfunction (failure of the pituitary) and tertiary disorder (a problem involving the hypothalamus). Once the baseline level of LH has been measured, a dose of GnRH is given by injection. A subsequent increase in the level of LH indicates that the pituitary responded to the GnRH and points to a disorder involving the hypothalamus. A reduced level of LH shows that the pituitary did not respond to the GnRH and suggests a disease involving the pituitary.

In Children

In young children, high levels of LH and FSH with the development of secondary sexual characteristics at an unusually young age are an indication of precocious puberty. This is much more common in girls than in boys. This premature development is usually due to a problem with the central nervous system and can have a few different underlying causes. Examples include:

  • Central nervous system tumor
  • Brain injury, trauma
  • Inflammation within the central nervous system (e.g., meningitis, encephalitis)
  • Brain surgery
Normal prepubescent levels of LH and FSH in children exhibiting some signs of pubertal changes may indicate a condition call "precocious pseudopuberty." The signs and symptoms are brought on by elevated levels of the hormones estrogen or testosterone. This may be caused by:

  • Hormone-secreting tumors
  • Adrenal gland tumors
  • Ovarian tumors or https://labtestsonline.org/glossary/cyst/
  • Testicular tumors
Normal FSH and LH levels with a few signs of puberty can also be a benign form of precocious puberty with no underlying or discernable cause or may just be a normal variation of puberty. In delayed puberty, LH and FSH levels can be normal or below what is expected for a youth within this age range. The test for LH response to GnRH in addition to other testing may help to diagnose the reason for the delayed puberty. Some of the causes for delayed puberty can include:

  • Failure of the ovaries or testicles
  • Hormone deficiency
  • Turner syndrome
  • Klinefelter syndrome
  • Chronic infections
  • Cancer
  • Eating disorder (anorexia nervosa)
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Is there anything else I should know?
Some drugs can cause LH to increase, such as anticonvulsants, clomiphene, and naloxone, while others cause LH to decrease, such as digoxin, oral contraceptives, and hormone treatments.

A recent nuclear medicine scan may interfere with results of the LH test if it is measured by a radioimmunoassay, which is seldom used any more.

LH is sometimes referred to as interstitial cell stimulating hormone (ICSH) in males.
 
Prolactin: The Test
Prolactin

How is it used?

Prolactin levels may be used for several reasons. Prolactin is a hormone produced by the pituitary gland and its primary role is to help initiate and maintain breast milk production in pregnant and nursing women.

Prolactin testing may be used, along with other hormone tests, to help:

  • Determine the cause of breast milk production not associated with pregnancy or breast-feeding (https://labtestsonline.org/glossary/galactorrhea)
  • Diagnose the cause of infertility and erectile dysfunction in men
  • Diagnose the cause of menstrual irregularities and/or infertility in women
  • Detect and diagnose tumors that produce excess prolactin (prolactinomas), monitor their treatment, and detect recurrences
  • Evaluate https://labtestsonline.org/glossary/anterior pituitary function or other pituitary disorder
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infertility or irregular menstrual periods
  • A man has symptoms such as decreased sex drive (libido), nipple discharge, or infertility or has a low testosterone level
When a person has a prolactinoma, prolactin levels may be ordered periodically to monitor the progress of the tumor and its response to treatment. They may also be ordered at regular intervals to monitor for prolactinoma recurrence.

Prolactin levels may be ordered, along with other hormone levels such as growth hormone, when a health practitioner suspects that a person has a pituitary disorder such as https://labtestsonline.org/glossary/hypopituitarism.

When a person has a condition or is taking medications that may affect dopamine production, prolactin concentrations may sometimes be monitored.

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Men and non-pregnant women will normally have only small amounts of prolactin in their blood. Prolactin levels do, however, need to be evaluated based on the time of day that they are collected. The levels will vary over a 24-hour period, rising during sleep and peaking in the morning. Ideally, a person's blood sample should be drawn 3 to 4 hours after waking.

A high level of prolactin (hyperprolactinemia) is normal during pregnancy and after childbirth while the mother is nursing.

A high level may also be seen with:

Levels of prolactin that are below normal are not usually treated but may be indicative of a general decrease in pituitary hormones caused by a pituitary disorder such as https://labtestsonline.org/glossary/hypopituitarism.

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lung cancer, and use of marijuana can cause moderate increases in prolactin.

Drugs that can cause an elevated prolactin include estrogen, tricyclic antidepressants, risperidone, opiates, amphetamines, hypertension drugs (reserpine, verapamil, methyldopa) and some drugs that are used to treat gastroesophageal reflux (cimetidine). Nipple stimulation may cause a moderate increase in prolactin blood level.

Low prolactin levels may be caused by drugs such as dopamine, levodopa, and ergot alkaloid derivatives.

Prolactinomas are often small. Along with prolactin levels, a health practitioner may do an MRI (magnetic resonance imaging) of the brain to locate and determine the size of the tumor as well as the size of the pituitary gland.
 
And for good measure
SHBG: The Test | Sex Hormone Binding Globulin

Shbg

How is it used?
The sex hormone binding globulin (SHBG) test may be used to help evaluate men for low testosterone and women for excess testosterone production. It may be ordered in conjunction with other tests to evaluate the status of a person's sex hormones.

SHBG is a https://labtestsonline.org/glossary/protein that binds tightly to the hormones testosterone, dihydrotestosterone (DHT), and estradiol (an estrogen). In this bound state, SHBG transports these hormones in the blood as biologically inactive forms. Changes in SHBG levels can affect the amount of hormone that is available to be used by the body's tissues.

Testing for albumin level and one or more other sex hormones, such as prolactin, estradiol, and LH (luteinizing hormone), may also be performed to evaluate a person's existing balance of hormones.

SHBG in men
SHBG and total testosterone levels may be ordered for an adult male to help determine the cause of infertility, a decreased sex drive, or https://labtestsonline.org/glossary/erectile/. Measurement of SHBG in addition to testosterone is especially helpful when total testosterone results are inconsistent with clinical signs.

Measurement of total testosterone in the blood does not distinguish between bound and unbound (bioavailable) testosterone but, as the name implies, determines the overall quantity of testosterone in the blood. In many cases, this is sufficient to evaluate excessive or deficient testosterone production. However, if a person's SHBG level is not normal, then the total testosterone may not be an accurate representation of the amount of testosterone that is available to the body's tissues.

Measurement of SHBG helps health practitioners assess bioavailable testosterone with a simple total testosterone measurement. Increased SHBG in men may be associated with symptoms of low testosterone levels (https://labtestsonline.org/glossary/hypogonadism/) because less testosterone is available to the body's tissues.

The Endocrine Society professional guidelines recommend measuring total testosterone in the initial screen for testosterone deficiency. If abnormal, the test is repeated on another day. If repeat results are low-normal and/or if SHBG is abnormal, they recommend one of the following:

  • Measure bioavailable testosterone (using ammonium sulfate precipitation or SHBG)
  • Calculate free testosterone from total testosterone and SHBG
  • Measure free testosterone (using a method called equilibrium dialysis)
SHBG in women
In women, small amounts of testosterone are produced by the ovaries and adrenal glands. Even slight increases in testosterone production can disrupt the balance of hormones and cause symptoms such as irregular or missed menstrual periods, infertility, acne, and excess facial and body hair (https://labtestsonline.org/glossary/hirsutism). These signs and symptoms and others are often seen with polycystic ovary syndrome (PCOS), a condition characterized by an excess production of male sex hormones (androgens). SHBG and testosterone testing may be useful in helping to detect and evaluate excess testosterone production and/or decreased SHBG concentrations and in evaluating women suspected of having PCOS.

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total testosterone, and perhaps free testosterone (as measured by a method called equilibrium dialysis), provides sufficient information. SHBG is ordered primarily when the total testosterone results do not seem to be consistent with clinical signs and symptoms, such as infertility, decreased sex drive, and https://labtestsonline.org/glossary/erectile in men or infertility, irregular menstrual periods, and excess facial and body hair in women.

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A high SHBG level means that it is likely that less free testosterone is available to the tissues than is indicated by the total testosterone test. A low SHBG level means that more of the total testosterone is bioavailable and not bound to SHBG. This information may be important in the overall evaluation of an individual with signs and symptoms of a condition related to excess or deficient sex hormone production.

Increased SHBG levels may be seen in:

  • Liver disease
  • Hyperthyroidism
  • Eating disorders (anorexia nervosa)
  • Corticosteroids or estrogen use (hormone replacement therapy and oral contraceptives)
  • Decreased sex hormone production (https://labtestsonline.org/glossary/hypogonadism/)
  • Pregnancy
Decreases in SHBG are seen with:

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total testosterone levels begin to decrease. In postmenopausal women, SHBG, testosterone, and estrogen concentrations decrease as hormone production by the ovaries tapers.
 
Took an ephedrine caffeine dose too close to bed. Now I can't sleep. I gotta be up in like 4 hours.

At least I've used this time constructively.
 
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