Trichorrhexis nodosa can be an inherited condition.

The condition may be triggered by things such as blow-drying, ironing the hair, over-brushing, perming, or excessive chemical use.

In some cases, trichorrhexis nodosa is caused by an underlying disorder, including very rare ones, such as:

• Thyroid gland not making enough thyroid hormone (hypothyroidism)
• Buildup of ammonia in the body (argininosuccinic aciduria)
• Iron deficiency
• Menkes syndrome (Menkes kinky hair syndrome)
• Ectodermal dysplasia (a group of conditions in which there is abnormal development of the skin, hair, nails, teeth, or sweat glands
• Trichothiodystrophy (inherited disorder that causes brittle hair, skin problems, and intellectual disability)
• Biotin deficiency (inherited disorder in which the body is not able to use biotin, a substance needed for hair growth)

Your hair may break easily or it may appear like it is not growing.

In African Americans, looking at the scalp area using a microscope shows that the hair breaks off at the scalp area before it grows long.

In other people, the problem often appears at the end of a hair shaft in the form of split ends, thinning hair, and hair tips that look white.

Your health care provider will examine your hair and scalp. Some of your hairs will be checked under a microscope or with a special magnifier usually used by skin specialists.

Blood tests may be ordered to check for anemia, thyroid disease, and other conditions.

If you have a disorder that is causing trichorrhexis nodosa, it will be treated if possible.

Your provider may recommend measures to reduce damage to your hair such as:

• Gentle brushing with a soft brush instead of aggressive brushing or ratting
• Avoiding harsh chemicals such as those used in straightening compounds and perms
• Not using a very hot hair dryer for long periods and not ironing the hair
• Using a gentle shampoo and a hair conditioner

Improving grooming techniques and avoiding products that damage hair will help correct the problem.

This condition is not dangerous, but may affect a person's self-esteem.

Call your provider if symptoms do not improve with changes in grooming and other home-care measures.

Hair shaft fracture; Brittle hair; Fragile hair; Hair breakage

James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM. Diseases of the skin appendages. In: James WD, Elston DM, Treat JR, Rosenbach MA, Neuhaus IM, eds. Andrews' Diseases of the Skin: Clinical Dermatology. 13th ed. Philadelphia, PA: Elsevier; 2020:chap 33.

Restrepo R, Calonje E. Diseases of the hair. In: Calonje E, Brenn T, Lazar AJ, Billings SD, eds. McKee's Pathology of the Skin. 5th ed. Philadelphia, PA: Elsevier; 2020:chap 22.

Updated by: Ramin Fathi, MD, FAAD, Director, Phoenix Surgical Dermatology Group, Phoenix, AZ. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.