Blood type and Rh factor
blood type test · blood group test · Rh factor · what is my blood type
This test shows your blood type and Rh factor: positive or negative. Blood is taken from a vein or a finger.
Before surgery, during pregnancy or when planning one, before a blood transfusion, and for medical records and documents.
⏱ Duration: taking the blood takes 1 to 3 minutes
Be sure to tell your doctor
How to prepare
- Food. Usually no special preparation is needed. If you are having other tests at the same time, come fasting as your clinic says.
- Water. Drink a glass of plain water. This makes it easier to take blood.
What to bring
- Your referral
- Your ID
How it goes
- You are asked to sit down and say your full name, so the tube is labeled correctly
- The nurse takes blood from a vein or a finger
- A cotton ball is put on the spot
- In the lab, the blood is mixed with special reagents to see the result
What you'll feel
- A quick needle prick
- Sometimes a small bruise stays after a vein draw
Afterwards
- Press the cotton ball for a few minutes
- You can go about your day right away
- The result is usually ready the same day or the next day
- Your blood type does not change in your lifetime. Keep the result
Common questions
Can my blood type change?
No. Blood type and Rh are set from birth and do not change. The exception is rare cases after a bone marrow transplant.
Why do pregnant women need to know their Rh factor?
If the mother is Rh negative and the baby is Rh positive, special monitoring is needed. The doctor will tell you which tests come next.
Why is my blood type checked again before surgery?
It is the safety rule. Before a transfusion, blood is always checked again, even if the type is known.