How to know if i'm a hypochondriac or real illness?

Ask your physician..: ...about your concerns. If you suffer from hypochondriasis, most likely you have had a number of physicians tell you there is nothing wrong despite medical history, physical exam findings and lab or imaging studies. You will keep going to physicians until you find one that will tell you that you are sick (you likely won't find one).

Real illness is: rule out medically. If there is a pattern of medical illnesses being repeated rule out and the person remains obsessed with health concerns that might be hypochondria.