I just have to mention here that it is very unusual for a 17 year old to be thinning all over to the extent of wanting a full cap. Most your age experience typical male pattern baldness. at 17, if you are thinning all over, it could be perfectly normal for you .......but I don't think it would hurt to get it checked out by a Dr. just to eliminate any other cause. Just to be safe.
DebbieS.