Alopecia areata is the best-known autoimmune disorder associated with hair loss. The body's immune system signals white blood cells to attack healthy cells in hair follicles. This causes the hair follicles to shrink, resulting in varying degrees of visible hair loss on the scalp and sometimes on the face and body.
In most cases, the hair falls out in small spots the size of a quarter. However, the disorder can lead to complete hair loss on the scalp (total alopecia) or, in severe cases, all over the body (universal alopecia).
Lupus
Hair loss occurs when antibodies created by the body infiltrate the hair follicles, causing the body to reject the hair shaft and fall out. Hair can grow back on its own during periods of remission.
Hashimoto's disease
Hair loss, increased sensitivity to cold, puffy face, hoarse voice, unexplained weight gain, and muscle aches increase if the condition remains untreated.
Some people experience hair thinning or large amounts of hair loss in the shower or sink. Changes in hair texture can cause it to become dry, rough, or easily tangled. In some cases, levothyroxine therapy can lead to prolonged or excessive hair loss as a side effect.
Graves disease
The disease causes antibodies to bind to the surface of thyroid cells, stimulating them and overproducing thyroid hormones.
It can also affect the production of new hair on the scalp and sometimes other parts of the body. Hormonal imbalance forces hair follicles to prematurely enter the resting or telogen phase of the hair cycle. This period lasts longer than usual, effectively stopping hair production. Eventually, hair loss is visible because new hair does not grow to replace the one that naturally falls out over time.
Psoriasis
Psoriasis, associated with characteristic raised, red, and scaly patches on the skin, affects millions of people worldwide. When the scalp is affected, psoriasis can be severe, causing flaking, redness, and sometimes itching.
Psoriasis generally does not cause large amounts of hair loss. If the flaking on the scalp is very tight, the diameter of the hairs can change and cause breakage. Psoriasis is often confused with the severe scalp condition, pityriasis amientacea, which causes distinctive hair loss.
Crohn's disease
Crohn's disease is an incurable inflammatory disease that affects any part of the gastrointestinal tract. Hair loss is a rare and minor symptom of Crohn's disease, which can cause severe abdominal pain and related problems.
Hair loss is caused by disease that prevents or limits the absorption of nutrients and vitamins from the hair that are normally absorbed through the wall of the intestine and seep into the bloodstream. This results in a nutritional deficiency that can cause the hair follicles to stop regenerating and begin to lose.