Armpits usually smell bad when sweat from the glands in this area is broken down by bacteria that live on the skin. This process creates strong-smelling substances that can lead to a sour, pungent, or “musty” odor, especially in closed, warm areas like the underarms. This condition is often referred to medically as bromhidrosis and is very common.
The smell can become stronger when there is more sweating, which can happen as a result of heat, exercise, stress, or hormonal changes during puberty. Poorly ventilated clothing, not drying the skin well after bathing, obesity, and some medications or health problems can also make odor worse. In some cases, excessive sweating itself may be part of the problem and may need its own evaluation.
Keeping the armpits clean and dry, changing clothes regularly, and using antiperspirant deodorants can help reduce odor for many people. When these basic measures are not enough, medical treatments such as antibacterial soaps, topical medicines, or procedures to reduce sweat gland activity may be considered
A dermatologist or family doctor is the most appropriate specialist to assess persistent or very strong underarm odor, rule out underlying diseases, and recommend safe treatment options.