I am 18. i am loosing my hair day by day. i don't have thick hair my scalp can be seen with light hair.how can i stop this?

Hair loss: check to see if early hair loss is on either side of your parents----if it is then it is genetic----hard to prevent--:( if there is not early hair loss then follow up with your doctor to check for infections or endocrine problems----light haired/blondes red/heads have a tendency to loss their hair easier

Finasteride, minoxid: See a dermatologist. The DR will make a diagnosis and help you decide about appropriate treatment. If you have ordinary androgenetic alopecia, you may wish to take finasteride or apply minoxidil or use both.