Women's hair loss can be classified into diffuse hair loss, localized hair loss, or patterned hair loss. It can also be divided into scarring and non-scarring types. Since the diffuse, non-scarring female hair loss caused by hereditary is so common, it has its own special classification that is based upon the degree of thinning called the Ludwig classification.

The Ludwig Classification uses three stages to describe female pattern genetic hair loss: Type I (mild), Type II (moderate) and Type III (extensive). In all three Ludwig stages, there is hair loss on the front and top of the scalp with relative preservation of the frontal hairline. The back and sides may or may not be involved. Regardless of the extent of hair loss, only women with stable hair on the back and sides of the scalp are candidates for hair transplant surgery.  

 Type I. Early thinning that can be easily camouflaged with proper grooming. Type I patients have too little hair loss to consider surgical hair restoration.

 Type II. Significant widening of the midline part and noticeably decreased volume. Hair transplantation may be indicated if the donor area in the back and sides of the scalp is stable.

Type III. A thin, see-through look on the top of the scalp. This is often associated with generalized thinning.