Understanding routine lab test results - lab test errors, abnormalities -aarp

En español l How’s your bilirubin level? And your BUN/creatinine ratio? Unless you enjoy reading Dictionary of Medical Terms, your routine lab results can seem downright cryptic. To help you

decipher them, we asked Mark S. Lachs, M.D., author of  _Treat Me, Not My Age_, and Marie  A. Bernard, M.D., deputy director of the National Institute on Aging, to explain what all those

numbers really mean. AARP MEMBERS ENJOY HEALTH AND WELLNESS DISCOUNTS You can save on eye exams, prescription drugs, hearing aids and more Just be aware: Abnormal test results are fairly

common, especially among older adults. “Fifty-plus folks tend to take more medications,” says Lachs, “and that can throw off test results. For example, diuretics can alter sodium and

potassium levels; heparin can decrease your platelet count.” (These are real abnormalities that may need further treatment.) Plus, many older adults have chronic conditions that require more

frequent testing — and the more you’re tested, the greater the likelihood of error. Finally, normal ranges are based on population averages, so normal for you might be slightly out of that

range and of no significance. For instance, if you have Gilbert’s syndrome, a common, mild liver condition, you’d show elevated bilirubin, which could otherwise signal a serious liver

dysfunction. “If you have known abnormalities, be sure to remind your doctor each time you get tested,” says Lachs.   It’s a good idea to schedule a doctor’s appointment after undergoing lab

work. That way, you can discuss any unusual results face-to-face. __ __ GLUCOSE (FASTING) WHAT IT IS Sugar in the blood NORMAL RESULTS 70 - 99 mg/dl WHAT A LOW NUMBER MAY MEAN 

Hypoglycemia, liver disease, adrenal insufficiency, excess insulin WHAT A HIGH NUMBER MAY MEAN  Hyperglycemia, certain types of diabetes, prediabetes, pancreatitis, hyperthyroidism __ __

SODIUM WHAT IT IS An electrolyte, which keeps your body in balance NORMAL RESULTS 136 - 144 mEq/L WHAT A LOW NUMBER MAY MEAN  Use of diuretics, diarrhea, adrenal insufficiency WHAT A HIGH

NUMBER MAY MEAN  Kidney dysfunction, dehydration, Cushing's syndrome __ __ POTASSIUM WHAT IT IS An electrolyte and mineral NORMAL RESULTS 3.7 - 5.2 mEq/L WHAT A LOW NUMBER MAY MEAN Use

of diuretics or corticosteroids (such as prednisone or cortisone) WHAT A HIGH NUMBER MAY MEAN Acute or chronic kidney failure, Addison's disease, diabetes, dehydration __ __ CHLORIDE

WHAT IT IS An electrolyte NORMAL RESULTS 96 - 106 mmol/L WHAT A LOW NUMBER MAY MEAN  Emphysema, chronic lung diseases WHAT A HIGH NUMBER MAY MEAN  Dehydration, Cushing's syndrome,

kidney disease __ __ CARBON DIOXIDE WHAT IT IS Gaseous waste product from metabolism NORMAL RESULTS 20 - 29 mmol/L WHAT A LOW NUMBER MAY MEAN  Kidney disease, certain toxic exposures, severe

infection WHAT A HIGH NUMBER MAY MEAN  Lung diseases, including COPD __ __ BUN: BLOOD UREA NITROGEN WHAT IT IS A waste product formed in liver and carried to kidneys, filtered out of blood,

 excreted through urine. NORMAL RESULTS 7 - 29 mg/dL WHAT A LOW NUMBER MAY MEAN  Malnutrition WHAT A HIGH NUMBER MAY MEAN  Liver or kidney disease, heart failure __ __ CREATININE WHAT IT IS

A chemical waste produced by muscle metabolism NORMAL RESULTS 0.8 - 1.4 mg/dL WHAT A LOW NUMBER MAY MEAN  Low muscle mass, malnutrition WHAT A HIGH NUMBER MAY MEAN  Chronic or temporary

decrease in kidney function __ __ BUN/CREATININE RATIO NORMAL RESULTS 10:1 to 20:1 WHAT A LOW NUMBER MAY MEAN  Malnutrition WHAT A HIGH NUMBER MAY MEAN  Blood in bowels, kidney obstruction,

dehydration __ __ CALCIUM WHAT IT IS A mineral stored in the hard part of bones NORMAL RESULTS 8.5 - 10.9 mg/dL WHAT A LOW NUMBER MAY MEAN  Calcium, magnesium, or Vitamin D deficiency;

malnutrition;pancreatitis; neurological disorders WHAT A HIGH NUMBER MAY MEAN  Kidney disease, hyperparathyroidism, cancer, excess vitamin D intake __ __ PROTEIN WHAT IT IS Chains of amino

acids essential for the growth and repair of cells NORMAL RESULTS 6.3 - 7.9 g/dL WHAT A LOW NUMBER MAY MEAN  Malnutrition, liver or kidney disease WHAT A HIGH NUMBER MAY MEAN  Liver or

kidney disease, dehydration, multiple myeloma __ __ ALBUMIN WHAT IT IS Protein that keeps fluid from leaking out of blood vessels and that nourishestissues and transports nutrients through

the body NORMAL RESULTS 3.9 - 5.0 g/dL WHAT A LOW NUMBER MAY MEAN  Liver or kidney disease, malnutrition WHAT A HIGH NUMBER MAY MEAN  Dehydration __ __ BILIRUBIN WHAT IT IS A pigment in the

bile, a digestive fluid produced by the liver NORMAL RESULTS 0.2 - 1.9 mg/dL WHAT A LOW NUMBER MAY MEAN  Generally not a concern WHAT A HIGH NUMBER MAY MEAN Liver disease, bile duct disorder

or red cell destruction __ __ ALKALINE PHOSPHATASE (ALP) WHAT IT IS Enzyme found in the liver and bones NORMAL RESULTS 44 - 147 IU/L WHAT A LOW NUMBER MAY MEAN  Malnutrition WHAT A HIGH

NUMBER MAY MEAN  Paget's disease or certain cancers that spread to bone, bile duct obstruction, liver cancer __ __ ALANINE AMINOTRANSFERASE (ALT) WHAT IT IS Enzyme found mostly in the

liver NORMAL RESULTS 8 - 37 IU/L WHAT A LOW NUMBER MAY MEAN  Generally not a concern WHAT A HIGH NUMBER MAY MEAN  Certain toxins such as excess acetaminophen or alcohol, hepatitis  __ __

ASPARTATE AMINOTRANSFERASE (AST) WHAT IT IS Enzyme found in liver, muscle, and other tissues NORMAL RESULTS 10 - 34 IU/L WHAT A LOW NUMBER MAY MEAN  Generally not a concern WHAT A HIGH

NUMBER MAY MEAN  Excess acetaminophen, hepatitis, muscle injury __ __ WHITE BLOOD CELL COUNT (WBC) WHAT IT IS White blood cells defend the body against infection NORMAL RESULTS 4,500 -

10,000 cells/mcL WHAT A LOW NUMBER MAY MEAN  Autoimmune illness, bone marrow failure, chemotherapy, viral infections WHAT A HIGH NUMBER MAY MEAN  Infection, inflammation, cancer, leukemia,

intense exercise, stress, corticosteroids __ __ RED BLOOD CELL COUNT (RBC) WHAT IT IS Red blood cells pick up oxygen from the blood and deliver it to tissues throughout the body NORMAL

RESULTS Male: 4.7 - 6.1 Mill/mcL Female: 4.2 - 5.4 Mill/mcL WHAT A LOW NUMBER MAY MEAN  Iron, vitamin B12, or folate deficiency; bone marrow damage WHAT A HIGH NUMBER MAY MEAN  Dehydration,

renal problems, pulmonary or congenital heart disease __ __ HEMOGLOBIN WHAT IT IS Oxyrgen-carrying pigment in red blood cells NORMAL RESULTS Male: 13.8 - 17.2 g/dL Female: 12.1 - 15.1 g/dL

WHAT A LOW NUMBER MAY MEAN  Iron, vitamin B12, or folate deficiency; bone marrow damage WHAT A HIGH NUMBER MAY MEAN  Dehydration, renal problems, pulmonary or congenital heart disease __ __

HEMATOCRIT WHAT IT IS The percentage of red blood cells in the blood NORMAL RESULTS Male: 40.7% - 50.3% Female: 36.1% - 44.3% WHAT A LOW NUMBER MAY MEAN  Iron, vitamin B12, or folate

deficiency; bone marrow damage WHAT A HIGH NUMBER MAY MEAN  Dehydration, renal problems, pulmonary or congenital heart disease __ __ MEAN CORPUSCULAR VOLUME (MCV) WHAT IT IS Average size of

red blood cells NORMAL RESULTS 80 - 95 fL WHAT A LOW NUMBER MAY MEAN  Iron deficiency WHAT A HIGH NUMBER MAY MEAN  Vitamin B12 or folate deficiency __ __ MEAN CORPUSCULAR HEMOGLOBIN (MCH)

WHAT IT IS The amount of hemoglobin in red blood cells NORMAL RESULTS 27 - 31 pg WHAT A LOW NUMBER MAY MEAN  Iron deficiency WHAT A HIGH NUMBER MAY MEAN  Vitamin B12 or folate deficiency __

__ PLATELET COUNT WHAT IT IS Measures number of platelets — colorless blood cells integral to clotting NORMAL RESULTS 150 - 400 Thous/mcL WHAT A LOW NUMBER MAY MEAN  Viral infections, lupus,

leukemia, chemotherapy, pernicious anemia (due to vitamin B12 deficiency) WHAT A HIGH NUMBER MAY MEAN  Leukemia, myeloproliferative disorders (which cause blood cells to grow abnormally in

bone marrow), inflammatory conditions __ __ DESIRED LEVELS TOTAL CHOLESTEROL <200 mg/dL HDL >40 mg/dL LDL <130 mg/dL TRIGLYCERIDES <150 mg/dL Photo by Science Photo Library/Getty

Images Frequent testing increases the likelihood of error. THESE FACTORS CAN THROW OFF RESULTS: * Running or any high-intensity exercise can cause slight dehydration and show up as kidney

insufficiency. * A sunburn can elevate white blood cell count, which typically signals inflammation. * Got a sick spouse or child but feel fine yourself? A nonsymptomatic cold virus can

raise or lower white blood cell count. * An improper blood draw can cause a potassium spike; eating too much licorice can make it drop. * A specimen that sits for too long before testing by

the lab can skew blood sugar readings. MEMBER DISCOUNTS! SAVE ON EYE EXAMS, PRESCRIPTION DRUGS, HEARING AIDS AND MORE ALSO OF INTEREST: HOW TO GET PATIENTS TO ASK — AND DOCTORS TO LISTEN.

RELATED * Want your test results? Don’t wait. Nag your doctor * What medical tests do you need after age 50? * Join AARP today and receive access to exclusive information benefits and

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