Afraid of getting bald

It's been years now that my husband experienced hair loss.Of course he doesn't like it.At first,he was afraid of becoming bald but fortunately it didn't happen.He just had some hair loss in the middle part of his head.I asked him,what are the reasons for hair loss.He told me that getting old is one of the reasons.But I told him that I have a cousin who is young,it was in his late 20s when he suffered losing his hair.He is now almost bald.I remember he was very studious,he really studied a lot and in fact he is now an electrical engineer working in a plant in Davao.Everytime he goes out,he always wear his cap or hat to hide his almost bald head.It's really bad if the hair don't grow back anymore.