LAB TEST
CBC blood test
A complete blood count (CBC) test measures the following: The number of white blood cells ( WBC count ) The number of red blood cells ( RBC count ) The number of platelets The total amount of hemoglobin in the blood The fraction of the blood composed of red blood cells ( hematocrit ) The CBC test also provides information about the following measurements: Mean red blood cell volume (MCV) Mean hemoglobin amount per red blood cell (MCH) The mean amount of hemoglobin relative to the size of the cell (hemoglobin concentration) per red blood cell (MCHC)
How the Test is Performed
A blood sample is needed.
How to Prepare for the Test
There is no special preparation needed.
How the Test will Feel
When the needle is inserted to draw blood, you may feel moderate pain. Some people feel only a prick or stinging. Afterward there may be some throbbing or slight bruising. This soon goes away.
Why the Test is Performed
A CBC is a commonly performed lab test. It can be used to detect or monitor many different health conditions. Your health care provider may order this test: If you are having symptoms, such as fatigue, weight loss, fever or other signs of an infection, weakness, bruising, bleeding, or any signs of cancer When you are…
Normal Results
Blood counts may vary with altitude. In general, normal results are: RBC count: Male: 4.7 to 6.1 million cells/mcL Female: 4.2 to 5.4 million cells/mcL WBC count: 4,500 to 10,000 cells/mcL Hematocrit: Male: 40.7% to 50.3% Female: 36.1% to 44.3% Hemoglobin: Male: 13.8 to 17.2 gm/dL Female: 12.1 to 15.1 gm/dL Red blood…
What Abnormal Results Mean
High RBC, hemoglobin, or hematocrit may be due to: A lack of enough water and fluids, such as from severe diarrhea, excessive sweating, or water pills used to treat high blood pressure Kidney disease with high erythropoietin production Low oxygen level in the blood for a long time, most often due to heart or lung…
Risks
There is very little risk involved with having your blood taken. Veins and arteries vary in size from one person to another, and from one side of the body to the other. Taking blood from some people may be more difficult than from others. Other risks associated with having blood drawn are slight, but may include:…
Considerations
RBCs transport hemoglobin which, in turn, carries oxygen. The amount of oxygen received by body tissues depends on the amount and function of RBCs and hemoglobin. WBCs are mediators of inflammation and the immune response . There are various types of WBCs that normally appear in the blood: Neutrophils…
References
Lin JC, Benz Jr. EJ. Approach to anemia in the adult and child. In: Hoffman R, Benz EJ, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 8th ed. Philadelphia, PA: Elsevier; 2023:chap 35. Means RT. Approach to the anemias. In: Goldman L, Schafer AI, eds. Goldman-Cecil Medicine . 26th ed.…
This is a summary. Read the full article at www.ucsfbenioffchildrens.org (reviewed 16/10/2022).
This page is general information and is not medical advice. It does not replace a registered doctor, and it is not a prescription or a recommendation to use any medicine or test. Prices are listed prices and may change. Always follow the advice of your doctor or pharmacist.