There are really no medical tests to diagnose acne. In fact, patients can usually self-diagnose. When you do visit a primary care physician or dermatologist, they will make what’s called a clinical diagnosis. This means that by examining your skin, they can determine whether or not you have acne. Acne is really common, especially in people who are going through puberty. However, acne comes and goes over time. If you have red bumps across your nose and cheeks that don’t go away, you may have something other than that. That’s why you should see a dermatologist to determine what is happening with your skin.