While it's often misdiagnosed, there is a cure if caught in time.
Chondra Hungerford could clean and jerk 200 pounds and bench press 185, but in a matter of months she went from a 120 pound muscle machine to 176 pounds.
"I was trapped in this body of a monster and I was horrified," said Hungerford, who says she was an Olympic power lifer and body builder before the weight gain.
Soon, she was diagnosed with hypo-thyroidism. She was also told she was allergic to her own hair follicles, and should be treated for mental problems.
"I didn't know what I was doing anymore," said Hungerford.
Tests revealed her testosterone level was 77; it should have been 40. Her cortisol level was over 1,400; normal is 30.
She started researching and found Dr. Hoi Sang U, who immediately tested her for Cushing's Disease. It is caused by a tumor in the pituitary gland.
"The life expectancy is very low. If you can correct it, however, your life completely turns around," said Dr. U, who said several of his patients have been referred to him from psych wards.
"These people were locked up. Psychotic," he said.
But he says finding the tumor can be difficult.
"Some of these patients could have full blown symptoms and appearance of Cushing's Disease, and yet when you do an MRI scan, you don't see a tumor," said Dr. U.
Dr. U successfully pinpointed Hungerford's tumor. He went through her nose, to the base of the skull where the pituitary gland sits and removed the tumor.
Four months later and 40 pounds lighter, Hungerford is back at the gym, working to regain her strength and her life.
After surgery, Hungerford did go through cortisol withdrawal because Cushing's Disease made her levels so high.
Symptoms for the disease include weight gain; acne or skin infections; and purple marks on the skin of the abdomen, thighs and breasts. Patients also experience excessive hair growth on their face, neck, chest, stomach and thighs.