At 18 years of age when you seem to have hair issues it is a sign that your life style needs to be changed. Do you sleep well, eat well and exercise? If the answer to any of the questions is no, then you will continue to have hair problems despite treatment. The hair indicates how healthy your body is. So modify your life style . Plus, hair treatment may or may not require prescription medicines and in your case the dermatologist will be able to decide the treatment only after examination of your scalp and hair. So visit a dermatologist and you will benefit .