Blood sample - capillary; Fingerstick; Heelstick
A capillary sample is a blood sample collected by pricking the skin. Capillaries are tiny blood vessels near the surface of the skin.
The test is done in the following way:
Some people feel moderate pain. Others feel only a prick or stinging sensation. Afterward, there may be some throbbing.
Blood transports oxygen, food, waste products, and other materials within the body. It also helps regulate body temperature. Blood is made up of cells and a fluid called plasma. Plasma contains various dissolved substances. The cells are mainly red blood cells, white blood cells, and platelets.
Because blood has many functions, tests on the blood or its components provide valuable clues in the diagnosis of medical conditions.
Capillary blood sampling has several advantages over drawing blood from a vein:
Disadvantages to capillary blood sampling include:
Results vary depending on the test done. Your health care provider can tell you more.
Risks of this test may include any of the following:
Garza D, Becan-McBride K. Capillary of dermal blood specimens. In: Garza D, Becan-McBride K, eds. Phlebotomy Handbook. 10th ed. Upper Saddle River, NJ: Pearson; 2018:chap 11.
Vajpayee N, Graham SS, Bem S. Basic examination of blood and bone marrow. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 24th ed. Philadelphia, PA: Elsevier; 2022:chap 31.BACK TO TOP
Review Date: 5/24/2021
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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