What Are the Causes of Underarm Odor?

Sweating is the body's way of cooling down after heavy exercise, fever or heat exposure, and it also acts as a skin hydrator. Perspiration trapped in areas such as the underarms can become a source of odor that can become very unpleasant if it the cause is not addressed.

Misconceptions

• Some people believe that underarm odor is a direct result of sweating and perspiration, but this is untrue. According to the Mayo Clinic, the perspiration that is released by the apocrine glands under the arms is actually a combination of water, salt and urea that is completely odorless on its own. It is not until it comes in contact with bacteria on the surface of the skin that unpleasant odors begin to manifest.

Bacteria

• National Geographic News reports that there is bacteria lurking all over the surface of human skin. The majority of these bacteria are good types that are important to the health of the skin. Bacteria are known to flourish in moist dark places---such as the armpit. When the bacteria are met with perspiration, it begins to break down. Underarm odor is ultimately caused by the decomposition of these bacteria.

Poor Hygiene

• Poor hygiene can play a major role in underarm odor. In order to control the bacterial growth that leads to body odor, regular bathing is a must. Hyperhidrosis.net recommends wearing clean clothing that is comprised of breathable fabrics is also important. The daily use of a combination antiperspirant and deodorant product can also help to kill the bacteria that causes underarm odor.

Hormones

• For some people, the causes of underarm odor are complex and involve more factors than bacteria and hygiene. In fact, 34-Menopause-Symptoms.com reveals that metabolism and hormones may also play a role, especially in women who are experiencing the hormonal changes that accompany menopause. Estrogen is the hormone that assists the hypothalamus portion of the brain in controlling body temperature. When estrogen levels fall, as they often do during menopause, the hypothalamus interprets the drop in estrogen as a sign that the body temperature is heating up. This scenario causes an increase in perspiration that when met with bacteria, significantly increases the chances of experiencing underarm odor.

Toxins

• Exposure to certain toxins may also make a person susceptible to underarm odor. Toxins that are released from the organs of the body can be excreted through the skin and linger on the surface of the body along with bacteria. In his book "Adrenal Fatigue: The 21st Century Stress Syndrome," Dr. James Wilson explains that fat-soluble toxins are automatically converted by the body into water-soluble toxins, which are excreted from the body in urine, bile and the lungs. Whatever water soluble toxins fail to exit through these systems will most likely do so via the skin. When these toxins are met with perspiration, underarm odor is likely.