Published: 2 Apr 2023

If the results are higher than recommended, you may be asked to go to your hospital for a full blood test.

Usually, the blood bottles contain small amounts of a chemical to stop your blood clotting in the tube, so it can be measured accurately in the lab. Blood tests are usually done to check how your body copes with illness, injury, inflammation, infection and some types of medication. Each bottle is labelled with your name, date of birth and hospital number, when the blood was taken, and has a different coloured top according to the type of test. If blood test results are abnormal, it gives the doctors a good indication of how to treat you or prevent problems occurring in the future.
This may be done in hospital or by your GP or practice nurse. If you're having an NHS health check, your blood test is usually a quick finger prick test that looks at the blood's glucose and cholesterol levels. A test for troponin can help to diagnose a heart attack, and a test for brain natriuretic peptide (BNP) can help diagnose heart failure.
If you take warfarin, your INR level (a measure of how quickly your blood will clot) will be tested regularly to make sure that you are prescribed the correct dose.Blood needs a very precise balance in order for your body to work well. These help monitor your risk of heart and circulatory diseases and diabetes, or how your condition is being managed.
Tests for different chemicals and proteins can indicate how your liver or kidneys are working. Then they are taken to be analysed.
Blood tests can be used for many different things, including to check cholesterol and blood glucose levels.

Blood tests are normally done by haematology department in the hospital or diagnostic center. Once you do have the results and you are unsure of what they mean, make sure you speak to the doctor again. This is where the doctor will be able to make you understand what could have gone wrong to begin with. When this happens, its best to talk to the doctor and understand why these tests have been recommended for you. A small sample of your blood is drawn. This is generally taken from a nerve in the middle of your elbow. Sometimes, based on the blood test results and the extent of the illness if any your doctor will come up with a treatment programme. Everyone takes a blood test at some point in their life. Sometimes, even if all the results do come back normal, you may be left with a nagging doubt on what the abnormality was in the first place. This helps prevent children from developing a fear of blood tests. For some people, the nerve at this point does not really show and that's when blood is drawn from the wrist. For children, a cream based anesthetic is rubbed onto the spot so that the pain from the needle is minimal.