Strange hair loss pattern

I'm 35 and have a strange hair loss pattern. I've been thinning for over 3 years now and will have periods where the hair stops falling out all together (for a couple months) then it starts again. I've been through the entire medical testing thing and no one can find anything.

My question is this: when the hair falls out, it seems to come out 4 or 5 strands at a time all from the same location. It also comes out in waves - like for 2 days it stops coming out all together and then it falls out like crazy for a day, a couple days or a week, then stops for a day. It's strange and never follows the same pattern. What hair I have left is turning gray extremely quickly. Has anyone else experienced this?

Incidently, I'm looking more for reasons than cures. I've gotten used to looking the way I do, I'd just like to know why it's happening.

Ellie Tweet