I am having a medical examination today. No, I am not ill. But I am a cancer survivor so I try to have my regular exams.
If you are over a certain age or have a family history of cancer you should talk to your doctor to see if you need to have tests run. This applies to heart disease, diabetes, and any number of physical problems.
You know your body better than anyone else. If you find lumps or bruises or anything else that cannot be explained see your doctor. If your body is not functioning the way it normally does see your doctor. If your doctor advises testing do it.
Most of the tests involve nothing more than a little discomfort and some time. Spare some time now so you will have the time later. Please.