It is normal to have some hair fall happening on a daily basis. Most people will lose up to 100 hairs per day. This is nothing to be concerned about. But if you are noticing large amounts of hair accumulating in combs and brushes or plugging up your drain, it may be time to seek some sort of treatment for your hair fall.
The most common reason for hair fall is androgenetic alopecia, more commonly known as male or female pattern baldness. This hair loss is caused by a hormone called DHT (dihydrotestosterone) that attacks the hair follicles located on the top and crown of the head. The hairs along the side and back of the head are immune to this hormone, so they do not fall out in any way that is of concern. Patients can have varying levels of this type of hair loss, and some patients may lose all of the hair affected by the DHT as soon as their early twenties. Others can last into their 80s and still be holding on to some hairs.