Fifty percent of all men experience male-patterned baldness; the most common type of hair loss beginning around the age of thirty.
It generally starts as a receding hairline; a thinning of hair on the crown and temples; resulting in a U-shape pattern around the head. In some rare cases, a male may end up completely bald.
The condition is genetic; caused by an abundance of the male hormone dihydrotestosterone (DHT) which causes the hair follicles to become weak and eventually inactive, resulting in a lack of hair re-growth. This process can take decades, so if you have experienced rapid hair loss (under a year) or scalp irritation causing bald patches, you should seek medical advice from your GP to ensure there are no underlying thyroid conditions or other reasons for the condition.
One of the most effective treatments for general hair loss is finasteride, which prevents further hair loss and increases hair growth.