Eyebrow hair loss?

18 years old are you male or female? The technical term for hair loss is Alopceia(I'm not sure if I spelled it right) some people have mild forms where they might just loose eye brows or lashes. If you are female you should have your hormones tested by your dr. Start with the general thyroid test. If no results pop up with that ask to see an endocrynologyst. They basicly are hormone guru's! they measure all the little hormones. If you have something out of balance they'll find it. Good luck