Causes of Underarm Hair Loss

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Most adult women shave under their arms to make their underarms more attractive, but occasionally the underarm hair will start to thin out and not grow in anymore. Although it may seem like a benefit to have thinner underarm hair, it can indicate an underlying health condition and should be looked at by a medical doctor.

Thyroid Disease

When the thyroid hormone is not released into the bloodstream like it should be, it can cause the systems in the body to not function properly. One of the ways that the body dysfunctions is to cause hair loss, which can be seen all over the body, including under the arms. If the underarms start to thin out or lose hair unexpectedly, it could be a symptom of a thyroid disorder.


Alopecia is a condition that causes rounded patches of hair loss on the scalp and body. It is worsened from stress and anxiety and can cause the follicles to constrict and suffocate the hair roots. Alopecia can effect the underarms, causing the hair to be lost in patches, rather than thinning out.

Adrenal Deficiancy

The adrenal glands control the distribution of growth hormones throughout the body, which regulate the growth of all parts of the body, including the bones, hair, muscles and tissues. If the adrenal glands are dysfunctional, it can inhibit hair growth. Because adrenal insufficiency is a serious medical concern, talk to your doctor right away if you suspect that underarm hair loss may result from adrenal problems.


Diabetes is a condition that causes the pancreas to not be able to produce or regulate insulin levels. This can result in blood sugar in the body becoming either too high or too low, which can cause all of the other systems in the body to not work properly. As a result, symptoms can be seen, such as hair loss, muscle weakness, confusion and kidney problems. Hair loss can occur all over the body, and is not centralized on the head. If underarm hair loss is accompanied by confusion, fatigue or kidney problems, talk to your doctor about taking a blood sugar test.


Malnutrition results from the body not receiving enough nutrients from the foods that are eaten. This can be caused by eating only processed foods, not taking a multivitamin or an intestinal parasite. Malnutrition can cause weight loss, tooth decay, and hair loss on the head and body, including the armpits. Taking a multivitamin can improve the body's functioning and can help increase hair growth.