22 Hard-To-Detect Illnesses, From The Commonplace To The Truly Bizarre

2. Diabetes

While type 1 diabetes is present at birth, type 2 develops after and causes serious problems with your body’s regulation of blood sugar. Some of the most obvious diabetes symptoms are feeling tired, thirsty or experiencing an increase in appetite. However, because all of these symptoms are common, it is hard to tell whether you are suffering from the disease, or your problems lay elsewhere.