What your blood reveals about you

By Times staff
© St. Petersburg Times,
published November 20, 2001

The rush to donate blood after the Sept. 11 attacks gave some donors a disturbing surprise: Screening tests for blood-borne diseases found they had HIV or hepatitis.

Blood tests done in your doctor's office or a hospital have a wide range of purposes. What exactly can your blood reveal about your health? When the nurse stabs your finger at an annual checkup, what will the lab be looking for?

Standard CBC (Complete Blood Count)

The basic test, and typically the only one needed. It checks:

1. Blood count -- Numbers of white cells, red cells and platelets and their sizes and shapes. An elevated white cell count, for example, may indicate an infection.

2. Anemia -- Hemoglobin, in the red blood cells, carries oxygen through the blood. Below-normal levels can indicate anemia.

Chem 7 (Profile 7 or Chemical Profile)

Looks at seven different blood chemicals, or components, most indicating how efficiently the body is handling wastes.

The first two are wastes from the kidneys.

1. BUN (blood urea nitrogen)

2. Creatinine

3. Blood sugar -- levels of glucose

The next three chemicals are related to electrolyte balance. For example, abnormal levels might indicate dehydration.

4. Sodium

5. Potassium

6. Chloride

7. Carbon dioxide -- Breathe in oxygen, breathe out carbon dioxide.

Specialized tests Lipid profile

The cholesterol test, advised every three to five years, or annually if you have a family history of high cholesterol or other risk factors, looks at good and bad triglycerides.

Prostate antigens

Level of prostatic specific antigens (PSAs) can indicate presence of prostate cancer.

Hepatitis

HIV

-- SOURCE: Information provided by Dr. Mark Multach, chief of general internal medicine at the University of Miami Medical School; and Dr. Nini Ku, pathologist at Bayfront Medical Center in St. Petersburg.

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