Complete blood count
CBC · FBC · full blood count · CBC with differential
This test shows how many red blood cells, white blood cells, and platelets you have, and your hemoglobin level. It is the most common blood test.
For checkups, before surgery, and when you have a fever, weakness, or a possible anemia or inflammation.
⏱ Duration: the blood draw takes 3 to 5 minutes; results usually come the next day
Be sure to tell your doctor
How to prepare
- Food. Morning is best, either fasting or a few hours after a light meal. Ask the lab.
- The day before. No alcohol and no hard workouts.
What to bring
- Your test request form
How it goes
- Blood is taken from a vein or a fingertip
- A band, antiseptic, and a quick prick
- Blood fills a tube, and a cotton pad is pressed on the spot
What you'll feel
- A quick prick
Afterwards
- Press the cotton pad for a few minutes
- Your doctor will explain the results. Numbers alone are not a diagnosis
Common questions
What is the sed rate?
It is how fast red blood cells settle in a tube. It goes up with inflammation, but can also be high without illness. Your doctor will judge it.
Do I need to fast?
It is better, but not strictly needed. After a fatty meal, the result may be less accurate.