BOSTON (CBSNewYork) – The “Mona Lisa” is probably the world’s most-famous painting.

Art experts have called the woman in Leonardo da Vinci’s portrait “mysterious.”

Now, a doctor has another word for her: Sick.

Dr. Mandeep Mehra is a medical director at Brigham and Women’s Hospital in Boston.

He’s been studying the woman in the da Vinci’s masterpiece, painted in the early 1500s.

She is believed to be the wife of a wealthy merchant.

Mehra points to a lack of eyebrows, receding hair line, a lesion near her left eye, a puffy neck and swollen hands.

His diagnosis?

A serious thyroid condition.