Zocdoc Answers

Medical questions & health advice by licensed doctors

"What is a CBC test?"

ZocdocAnswersWhat is a CBC test?


What is the point of a CBC? I had low energy levels for a long time, and then I started having tingling sensations in my fingers and hands. My doctor said she wanted to run a CBC test on me. I haven't done it yet - what can it actually tell us?


The term CBC is short for a complete blood count. It is a test that allows doctors to determine the different levels of different types of blood cells and platelets in your blood. It is a very common test, and requires a simple blood draw. The test results of the CBC give doctors information about the levels of white blood cells which help fight infection, red blood cells which carry oxygen throughout your body, and platelets which help you body stop bleeding after a cut. Given your low energy levels your doctor is likely concerned about anemia. A complete blood count is the first and most basic way to begin the work-up for anemia. The results of the test will not only tell your doctor if your red blood count is low, but also will give your doctor clues as to why it might be low. There are many reasons to be anemic, and some of the most common are bleeding, low iron levels, and vitamin deficiencies. The results of the CBC test will help direct your doctor as to which is the most likely cause. Given your other symptoms of tingling sensations in your fingers your doctor is likely concerned that low vitamin B12 is reason for both your fatigue and the numbness and tingling. You should talk with your primary care physician about the best way to further evaluate and treat your symptoms.

Zocdoc Answers is for general informational purposes only and is not a substitute for professional medical advice. If you think you may have a medical emergency, call your doctor (in the United States) 911 immediately. Always seek the advice of your doctor before starting or changing treatment. Medical professionals who provide responses to health-related questions are intended third party beneficiaries with certain rights under Zocdoc’s Terms of Service.