15. Skin darkening
This condition is also known as acanthosis. It involves darkening, and sometimes thickening, of the skin, particularly in folds. The darkened skin can sometimes have a velvety texture and be raised. It is most often found under the breasts, armpits or neck.
Acanthosis Nigricans is considered by doctors to be a sign of diabetes. It may also be linked to insulin resistance.
