Why does underarm sweating cause excessive sweating?

Sweating normally helps regulate body temperature. In axillary hyperhidrosis, nerve signals to the sweat glands can be overactive, so the glands produce more sweat than the situation requires. The armpits contain many sweat glands and are a common site for noticeable moisture. Heat, exercise, stress, or strong emotion may increase sweating, but episodes can also occur when the body is cool and at rest.

Sweat itself is usually clear and has little smell when released. Odour develops when skin bacteria break down components on the skin. Damp clothing, chafing, and embarrassment can make the problem more disruptive even when the skin looks normal.

Apply an antiperspirant to completely dry underarm skin, often in the evening according to the product directions, and wash it off as advised. Choose breathable clothing, change damp garments, and protect irritated skin from friction. If regular products are not enough, a clinician can discuss prescription antiperspirants, injections, medicines, or other treatments based on your health and symptoms.

Make an appointment if sweating is new, worsening, disrupting work or sleep, or occurring across the body. Medical review is especially useful when sweating began after a medicine or comes with weight change, tremor, fever, palpitations, or night sweats. Seek urgent help for sudden sweating with chest pressure, faintness, severe breathlessness, or confusion.

Ask whether the pattern fits axillary hyperhidrosis, whether a medicine or medical condition could contribute, and which treatment is suitable for your underarm skin.