Several factors can cause hair loss, both in men and in women. This can include everything from health issues to damage caused by chemical treatments or hair products. However, for men a primary cause is male pattern baldness, which is a major concern for many men as they enter middle age. In fact, according the U.S. National Library of Medicine, over half of men aged 50 and over will experience some degree of male pattern baldness. But what exactly causes this very common affliction? Read on to learn more about the causes of baldness in men.