Deciphering Blood Test Measurements
Additional Resources for Faculty and Staff
Blood tests use the metric measurement system and abbreviations such as the following:
|cmm||cells per cubic millimeter|
|fL (femtoliter)||fraction of one-millionth of a liter|
|g/dL||grams per deciliter|
|IU/L||international units per liter|
|mEq/L||milliequivalent per liter|
|mg/dL||milligrams er deciliter|
|mmol/L||milligrams per liter|
|ng/mL||nanograms per milliliter|
|pg (picograms)||one-trilionth of a gram|
The following are tested with the biometric screening, or are offered at an additional cost**
|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.
|BUN (blood urea nitrogen)||
Healthy Range: 10 to 20 mg/dL
This is a 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.
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.
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).
|HDL (Good) cholesterol||
General rules (best to worst):
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||
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.
Healthy 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.
|Hemoglobin (Hgb)/ Iron||
Healthy 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.
|WBC (white blood cell) differential count||
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 calls are in proper proportion to each other. Irregularities in this test could signal an infection, inflammation, autoimmune disorders, anemia, or other health concerns.
|WBC (white blood cell) leukocyte count||
Healthy 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.
|RBC (red blood cell) erythrocyte count||
Healthy 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.
|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.
General rules (best to worst): American Heart Association
When your heart beats, it pumps blood around your body to give it the energy and oxygen it needs. As the blood moves, it pushes against the sides of the blood vessels. The strength of this pushing is your blood pressure.
|Liver Enzyme Testing||
Healthy Range: Ranges from about 7 to 56 units/liter, and 10 to 40 units/liter for AST
This test looks at the levels of the liver enzyme ALT.
|Serum 25-HydroxyvitaminD [25 (OH)D]||
Healthy Range: 30 - 50 nmol/L or 12 to <20 ng/ml
Healthy Range: Vitamin B12 status is typically assessed via serum or plasma vitamin B12 levels. Values below approximately 170–250 pg/mL (120–180 picomol/L) for adults  indicate a vitamin B12 deficiency. However, evidence suggests that serum vitamin B12 concentrations might not accurately reflect intracellular concentrations . An elevated serum homocysteine level (values >13 micromol/L)  might also suggest a vitamin B12 deficiency. However, this indicator has poor specificity because it is influenced by other factors, such as low vitamin B6 or folate levels . Elevated methylmalonic acid levels (values >0.4 micromol/L) might be a more reliable indicator of vitamin B12 status because they indicate a metabolic change that is highly specific to vitamin B12 deficiency [5-7],.
Healthy Range: Normal serum magnesium concentrations range between 0.75 and 0.95 millimoles (mmol)/L [1,5]. Hypomagnesemia is defined as a serum magnesium level less than 0.75 mmol/L . Magnesium homeostasis is largely controlled by the kidney, which typically excretes about 120 mg magnesium into the urine each day . Urinary excretion is reduced when magnesium status is low .
|Thyroid Screening (cost: $15) **||
Healthy Range: (TSH) 0.3 to 3
Thyroid screenings are helpful for identifying problems with the thyroid gland. Many people who have issues with their thyroid gland experience fatigue and weight gain, or weight loss and feelings of nervousness or hyperactivity.
|Hemoglobin A1C **||
Healthy Range: An A1C level below 5.7% is considered normal. An A1C between 5.7% and 6.4% signals pre-diabetes. Type 2 diabetes is diagnosed when A1C is over 6.5%
The A1C test result gives a picture of the average amount of glucose in the blood over the last 2-3 months. the hemoglobin A1C test may be used to screen for and diagnose diabetes and prediabetes in adults.
|Prostate Screening (PSA) **||
Healthy Range: There is no specific normal or abnormal level of PSA in the blood. In general, however, the higher a man's PSA level, the more likely it is that he has prostate cancer. Moreover, continuous rise in a man's PSA level over time may also be a sign of prostate cancer.
Prostate-specific antigen, or PSA, is a protein produced by cells of the prostate gland. The PSA test measures the level of PSA in a man's blood. A positive PAS test can be a lifesaver for some men, identifying prostate cancer that needs treatment early.