The purpose of screening is early diagnosis and treatment. Screening tests are usually administered to people without current symptoms, but who may be at high risk for certain diseases or conditions.
A hematocrit or a hemoglobin test can detect anemia. These tests are part of a complete blood count, which is often done when you go to the doctor for an annual physical exam, or as part of your prenatal exams. A hematocrit is done every time you give blood. Infants and children are often screened for iron deficiency anemia as part of a well child evaluation.
—The percentage of your blood that is red cells. This is easily done by filling a tiny glass tube with a drop of blood from your finger and spinning it down in a centrifuge so that all the cells settle to the bottom. Normal adult values are 42%-52% in men and 37%-48% in women.
(varies with altitude)
—The amount of hemoglobin (oxygen-carrying chemical) in your blood. Normal adult values for men are 13.8–17.2 grams per deciliter of blood (g/dL) and 12.1–15.1 gm/dL for women .
Complete Blood Count
—The above values plus a count of red cells, white cells, and platelets can be done automatically by a machine. These values plus calculations derived from them constitute the CBC, which is a routine blood test.
Few medical societies or organizations in America recommend complete blood count tests as part of a screening on routine physical exams. The US Centers for Disease Control and Prevention recommends screening for some children (especially those who were premature, consume more than 24 ounces of cow’s milk daily, or have certain health problems or dietary patterns predisposing them to anemia), for non-pregnant women at 5–10 year intervals (more often for those at risk of iron-deficiency because of heavy menstrual blood loss or poor iron intake), and for pregnant women at the first prenatal visit.
There are no recommendations for screening men or post-menopausal women. However, you will have a hematocrit every time you donate blood.
Recommendations to prevent and control iron deficiency in the United States. Centers for Disease Control and Prevention.
Harrison's Principles of Internal Medicine
. 16th ed. McGraw-Hill; 2004.
US Preventive Services Task Force. US Department of Health and Human Services. Agency for Healthcare Research and Quality website. Available at:
. Accessed February 2007.
Please be aware that this information is provided to supplement the care
provided by your physician. It is neither intended nor implied to be a
substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER
IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the
advice of your physician or other qualified health provider prior to
starting any new treatment or with any questions you may have regarding a