Jumping into a hot shower or running out to the car right after a game can upset your body's normal sweating system. If your relatives are showing signs of it, you have a good chance as well. Males tend to go bald in the horseshoe shape while females tend to have more of a general thinning all over the head. You might get some hints on this by looking at pictures of your grandfather in his later years. Sometimes baldness is a result of a medical condition, prescription drug, or chemotherapy for cancer treatment.
Males tend to lose their hair in what's known as 'male pattern balding'.
The resulting look is that of a horseshoe of hair around the back and sides of the head. Balding is generally a result of the hair follicles NOT growing any new hair shafts. Hair grows for about three months averaging one. The hair follicle then goes into hibernation for about a month. After this time period, a new hair shaft grows from this follicle and pushes the old shaft out.