There can be literally hundreds of reasons for hair fall in an individual. Hair Loss can be declared when you lose more than 100 strands of hair per day for more than a couple of weeks and still loosing. In most men, hair loss is genetic and it is the worst of all. Please note that this one is almost impossible to be treated, but can be slowed down. In genetic hair loss, the hair starts to thin out and stuns the growth of the hair and the individual eventually goes bald with time. Other common reasons are bad hygiene of the hair scalp (most common), fungal/bacterial infection, reaction to some disease or medicine, unhealthy products for hair, grooming that can harm the hair, etc. Due to bad hygiene of the scalp, the sweat buildup can attract and accumulate dirt and oil and eventually block the scalp pores. This will weaken the hair root and make it fall off. Also, the sweaty and oily scalp can cause fungal infection which is very harmful and disgusting for your hair health. DO SOMETHING IMMEDIATELY, if you feel constant itching and redness on your scalp.