Hair transplant surgeons describe hair loss in patients using classification systems. Classification systems can provide several advantages. They can help to determine what therapies or surgical procedures to use and help to standardize hair loss terminology, enabling better communication between hair transplant surgeons. Some systems are more comprehensive than others and the majority of systems are gender specific1–4. The most common classification system used to describe hair loss in men is the Hamilton-Norwood system and in women, the Ludwig system is typically used5.
In the 1950s, Hamilton categorized hair loss into eight types (I-VIII). Non-balding men were categorized as type I to III and balding men were categorized as type IV to VIII2,5. Hamilton based these categories on frontal hair recession and thinning patterns that were observed in over 300 men who were experiencing hair loss5. In 1975, Norwood revised this system based on where hair thinning starts such as in the temple and crown areas and then progresses along the top of the scalp4,5. The main hair loss classification system used in women, the Ludwig system, was developed in 1977 by Ludwig3. Women’s hair loss was classified into three different grades (I-III). A grade 1 women typically experienced thinning along the crown region and a grade 3 women experienced complete baldness3. Other classification systems that focus on hair loss in women include a five-stage classification system developed by Ebling and Rock, an eight stage system developed by Savin (nicknamed the Savin scale), and a self-reporting photographic based scale developed by Sinclair5,6.
If you are curious about what class your hair loss might be considered be sure to ask your hair transplant surgeon at your next consultation.
Article by: Sarah Versteeg MSc, Mediprobe Research Inc.
- Koo SH, Chung HS, Yoon ES, Park SH. A new classification of male pattern baldness and a clinical study of the anterior hairline. Aesthetic Plast Surg. 2000 Feb;24(1):46–51.
- Hamilton JB. Patterned loss of hair in man; types and incidence. Ann N Y Acad Sci. 1951 Mar;53(3):708–28.
- Ludwig E. Classification of the types of androgenetic alopecia (common baldness) occurring in the female sex. Br J Dermatol. 1977 Sep;97(3):247–54.
- Norwood OT. Male pattern baldness: classification and incidence. South Med J. 1975 Nov;68(11):1359–65.
- Gupta M, Mysore V. Classifications of Patterned Hair Loss: A Review. J Cutan Aesthetic Surg. 2016 Mar;9(1):3–12.
- Sinclair R, Jolley D, Mallari R, Magee J. The reliability of horizontally sectioned scalp biopsies in the diagnosis of chronic diffuse telogen hair loss in women. J Am Acad Dermatol. 2004 Aug;51(2):189–99.