Hair loss

I am losing my hair in patches. It first started in the beard. The hair becomes grey and then falls off. The problem started a year ago and the patches are expanding.

 

If the skin of the bald patches is normal, were not preceded by any skin eruption, and are asymptomatic, then you most likely have a disorder called Alopecia Areata. This is a self limiting disorder and can come and go for a few years. This can affect any hairy part of the body. It does not adversely affect any other system of the body. A number of medicines are useful. However systemic steroids should be avoided as much as is possible.
One can lose hair in patches in some other conditions also like Pseudopelade, Lichen Plano Pilaris, etc. In these conditions skin is atrophic and the hair lost will not come back. One tries to halt or slow down the progress of the disease.
In fungal infection also hair can be lost in patches. However fungal infections of this kind, over the scalp, are rare at your age. However these can easily be demonstrated in the hair stumps.