A blood test is when a sample of blood is taken for testing in a laboratory. Blood tests have a wide range of uses and are one of the most common types of medical test. For example, a blood test can be used to:
- assess your general state of health
- see how well certain organs, such as the liver and kidneys, are functioning
- confirm the presence of an infection
Blood tests are only performed when they are medically necessary and must be requested or authorised by your GP or nurse.
If a hospital doctor or clinic has asked you to have a blood test taken then this blood test would normally be arranged by the doctor that has asked for the test. This might be at the hospital clinic, or at a blood test 'Monitoring Clinic' at East Lothian Community Hospital, or sometimes with the CTACS (Community Treatment And Care Service) team.
A blood test usually involves the phlebotomist (person who takes blood samples) taking a sample from a blood vessel in your arm. The usual place for a sample is the inside of the elbow, where the veins are close to the surface. Blood samples from children are sometimes taken from the back of the hand. The child's hand can be anaesthetised (numbed) with a special cream before the sample is taken.