20 Early Symptoms of Diabetes You've Probably Ignored

14. Dark skin patches

High blood sugar level can cause the darkening on your skin, which is called acanthosis nigricans in its medical name, these discoloration occurs as your body’s production of skin cells increase with high insulin levels, causing increased pigmentation, giving your skin a dark color patch. The dark patch usually occurs on the back of your neck, armpit, or groin areas.