My daughter is almost 15. She has a dark ring around her neck and very dark underarms and a patch of dark skin between her breasts. She is 5ft. 4in. and weighs 150 pounds. The doctor checked her insulin level and it was low normal. Her glucose is normal so far when they have tested it. They haven't done a Glucose tolerance test or anything else. Does anyone have any ideas about why she would have this or is there any other tests she should get. She also has daily headaches, sometimes very bad or at least bad enough to take something for it. I would appreciate any suggestions as to the cause or what to do about it or anything that may be of help.

Thanks,
Mereja