Premature graying and hair loss are associated with hypothyroidism and should be taken seriously at any age.
Don't accept being told your thyroid tests are "normal", though, if you have symptoms of thyroid imbalance. You need a doctor that knows and listens to symptoms. Thyroid imbalance is often hereditary. When I discovered my first gray hair at age 19, I thought, OK, I just have hair like my mother, who began dying her hair at an early age. Turns out, it is exteremely likely she was hypothyroid, though she died before it was diagnosed, and I AM hypothyroid. Thyroid imbalance is a fairlycommon problem, and it is a serious one that leads to all kinds of problems, since the Thyroid's job is to keep all things balanced in the body.
You can find a symptom check-list on the Thyroid Board. Here is a link to it-
Information Archive [url="http://www.healthboards.com/ubb/Forum118/HTML/000005.html"]http://www.healthboards.com/ubb/Forum118/HTML/000005.html[/url]