You won’t know if you have leukaemia until your doctor has yarned with you, done a physical examination and completed some tests. The tests might include: blood tests a test on your bone marrow, which usually means they put a needle into a bone in your hip and take a sample genetic tests, which are usually a blood test a lumbar puncture, which is a test on the fluid in your spine tests such as a CT scan or MRI scan to see what your insides look like   biopsy of a lump or growth, usually a lymph node which is looked at under a microscope.Most people who have these tests find out they don’t have cancer, but it’s important to check.