I am a 42 year old Indian female. Recently, my face has become much darker (about 2 to 3 times darker) than my neck or hands or rest of the body. Have had irregular periods and on medication, which is being fixed. Been getting hot flushes, with body feeling hot from time to time. Many tests done for various things, but all negative. The dark face and hot flushes continue. Not pregnant, or no other known problems. Would appreciate any advice.