Medically known as alopecia. There are many types of baldness, each with a different cause. Baldness may be localised to the front and top of the head, as in the very common type of male-pattern baldness; baldness may be patchy, a condition called alopecia areata; or it may involve the entire head, as in alopecia capitis totalis. The word "alopecia" comes from the Greek "alopex" for "fox. " Foxes are less furry when afflicted with a skin disease called the "mange" which causes them to lose their hair. When a fancier word for "baldness" was sought, the mangy fox supplied it, "alopecia" or, if you wish, "fox-mange", not a very positive image to associate with baldness!