In Stage One, the hair is still healthy and thick. At this point, there are no indications of hair loss, such as bald patches or a receding hairline or baldness. The hair simply appears youthful and full.
Stage Two brings about the very earliest signs of hair loss. This includes a hairline that is only slightly beginning to recede (typically around the temples).
Stage Three sees the receding hairline creeping back even further from the face. Usually this results in either a U, W, or V shape on the top of the head when viewed from above.
By Stage Four, hair loss is much more noticeable. The crown of the head is either bald or has very sparse hair. The hair between the crown and the receding hairline is thinning. The receding hairline may, at this point, have a deep U shape when viewed from above.
Stage Five is much like Stage Four, only more severe. The section of hair between the crown of the head and the receding hairline is very small, and getting thinner and thinner. By this time, it will be much more difficult to see success from hair loss treatments.
Stage Six sees the bridge of hair disappear, causing the bald areas to join together. Hair on either side of the head may still be present, but the crown and front of the head are now essentially bald.
At Stage Seven, an individual is considered bald. Typically in this stage, no hair is left except for around the sides of the head.