Stop Hair Loss From Stress

Thinning hair at 18 is stress or genetics?

I just returned from Japan a few months ago and while I was there I had no problems with my hair. While in Japan under unbearable stress almost 24 hours a day, so when I finally arrived at the house exploded. While So I realized that my hair as I ran my fingers through it. This has been a month and I stopped losing hair, but is much thinner than ever. The father of my mother and the Most men beside my father's hair was fine, but it all started well in their forties. I think it may be genetic, but what is my story family on record that I do not know if it was the stress that acted as a placebo for my hair loss or if it is another stick I got the short gene.

Could be on the basis of two things.

Will working out prevent hair loss?