What could be the cause of darkening of joints?

Q: My knees, ankles, elbows and now my finger joints have darkened. These areas do not itch or hurt but they appear dirty. I have scrubbed but no change. Do you have any suggestion? I am not sure if this has anything to do with this, but I stopped having periods when I was in my early 30s.

A:Yes, it may be related. Get yourself checked for thyroid diseases and also if you have any deficiency of vitamins like vitamin A, B group.