Body odor is the unpleasant smell caused by the mixing of perspiration, or sweat, and bacteria on the skin. Sweat is generally an odorless body secretion. When bacteria multiply on the skin and break down these secretions, however, the resulting by-products may have a strong and disagreeable odor. This odor is often due to poor personal hygiene, but excessive perspiration or some other underlying disease is sometimes involved.
Causes & symptoms
People produce two kinds of sweat, eccrine and apocrine. Eccrine sweat glands secrete a mixture of water , salt (sodium chloride), urea, and lactic acid onto the skin. When a person is overheated, sweat seeps over the body, especially where the eccrine glands are numerous. These glands are concentrated in the armpits, the palms of the hands, the soles of the feet, and the forehead. As the sweat dries off, the skin is cooled by the surrounding air. Eccrine glands do not release any tissue cells or cell contents into their watery secretions.
In contrast with eccrine sweat, apocrine sweat is a heavier liquid containing various organic substances, including pheromone hormones. These glands are found mostly under the arms and around the groin. They develop during puberty, and are thought to serve a biological function in sexual attraction. Apocrine glands take their name from the fact that these glands release the apical portion, or tip, of the secreting cell into the liquid along with the other substances.
Sweat is essentially odorless when it is secreted, and the sweat from the eccrine glands remains so. It creates, however, a moist environment in which some of the bacteria that naturally occur on human skin can multiply. These bacteria are attracted to the sweat produced by the apocrine glands, and a strong odor is produced when these substances interact. On the other hand, however, the eccrine sweat glands may also help to regulate the types of bacteria on the body surface. Researchers in Germany have recently discovered that these glands secrete a peptide that has antimicrobial properties strong enough to kill some disease bacteria.
People who have a condition known as hyperhidrosis tend to sweat excessively, and therefore, they are more likely to develop a strong body odor. Bromhidrosis is the name for a medical condition in which an individual's sweat always has an unpleasant odor.
The human body normally has a slight sweaty or musky odor. Generally, bathing with soap and water, together with the use of deodorants or antiperspirants, is sufficient to prevent a truly unpleasant, unhealthy odor. There are, however, several factors that may contribute to chronic body odor. These include:
- Poor hygiene and inadequate bathing.
- An imbalance in the bacteria that inhabit the gut. Antibiotics may contribute to this condition.
- An inborn error of metabolism or some other problem that may cause about 7% of those suffering from body odor to be unable to digest certain foods. These undigested foods, which are often proteins, cause the body to give off unpleasant odors.
- Certain medications, including bupropion (Wellbutrin), venlafaxine (Effexor), tamoxifen, and pilocarpine (Salagen). These drugs may be responsible for the excretion of odors.
- Such disease conditions as liver disease, kidney disease, diabetes mellitus , a yeast infection, fungal infections , or gastrointestinal disorders may lead to body odor.
- Pathological skin conditions, including cancer, hemorrhoids , and ulcers, may produce unpleasant smelling discharges on the skin or body surface.
- Coffee and other stimulants increase apocrine gland secretion, increasing the possibility of unpleasant odors.
- States of high anxiety and stress that stimulate perspiration may increase the risk of body odors.
- Chain-smoking and heavy drinking. Alcohol and nicotine increase the rate of perspiration.
Since body odor may be caused by an underlying condition, a thorough medical exam is recommended along with a blood screen and blood chemistry panel.
The following remedies are mostly for the topical relief of body odor. For more thorough treatment, the underlying conditions should also be addressed.
- Two or three charcoal capsules per day for several weeks can help absorb waste products and reduce fermentation that may be causing body odor.
- Chlorophyll tablets can be taken by mouth to absorb body toxins and odors.
- Sage tea, Salvia officinalis, or sage extracts can be taken internally and an undiluted alcohol extract of sage can be used under the arms.
- Essential oils of rosemary , Rosmarinus officinalis, and thyme , Thymus vulgaris, can be used under the arms or on the feet.
- Baking soda or body powder will keep affected areas dry and absorb or mask odors.
- The diet should be improved to improve digestion, ensure regular bowel movements, and resolve constipation . There should be an increased intake of fluids to flush the system; six to eight glasses of water should be consumed daily.
Mostly topical treatments are recommended. These include the use of antiperspirants containing chlorhexidine or aluminum chloride applied under the arms, around the groin, on the feet, or under the breasts to relieve odor and wetness. Deodorant preparations that do not contain antiperspirants also work well. Topical antibacterial creams or lotions may also be used. In cases of unrelieved excess sweating, a physician may suggest surgical removal of the sweat glands beneath the armpits.
Good hygiene practices are important in preventing body odor. These include regular baths or showers; wearing cotton socks and non-synthetic shoes that breathe; changing the socks once or twice daily; and keeping the feet dry and bare as much as possible. Special foot powders and odor-absorbing shoe inserts may be helpful if foot odor is a particular problem.
Some foods and spices can intensify body odor. Onions, garlic , and cumin contain oils that may cause odor as they are excreted through the skin. Caffeine and nicotine increase sweating and therefore the risk of odor.
Dollemore, Doug, and the Editors of Prevention Health Books for Seniors. The Doctor's Book of Home Remedies for Seniors. New York: St. Martin's Press, 2000.
The Editors of Prevention Magazine Health Books. The Doctor's Book of Home Remedies II: Simple, Doctor-Approved Self-Care Solutions for 146 Common Health Conditions. Emmaus, PA: Rodale Press, 2002.
Stephenson, Joan. "Sweat Defense." Journal of the American Medical Association 286 (December 12, 2001): 2801.
HealthWorld Online. <http://www.healthy.net>.
Rebecca J. Frey, PhD