Hello Happy
Welcome to HealthcareMagic.Hair loss can be temporary or permanent. The former could be due to stress, a very common cause, certain vitamin deficiency, some medicines, infections(fungal)or even hormonal changes, for that matter.And cause of permanent hair loss is generally hereditary condition called Androgenetic alopecia, or by damage occuring to the hair follicle and or scalp.Hair loss in men is generally due to androgenic pattern baldness, which is usually referred to as male pattern baldness (MPB). The exact cause of pattern balding is not very clear though, the trait is transmitted by means of a polygenic type of inheritance.Its also seen to have a stronger link on maternal side.So you have to correlate with your personal history and try to avoid any known causes.And as regards medications minoxidil and finasteride are considered drugs for this kind of problems, although its efficacy is vey much individualistic.There is also option of hair transplantation. But all these can be better advised by your skin/ hair doctor after seeing you only.So please consult one soon.Hope I could answer your query. Take care.