Body Odor

Body odor occurs when a person's sweat comes into contact with the bacteria that are growing on the person's skin. All people sweat and have the potential to produce body odor. There are several factors that contribute to body odor. Some people may suffer from conditions that create excessive sweating, and some people's body odor may be more offensive than others.

What Is Body Odor?

Body odor is the smell of bacteria * reproducing in the sweat that is present on a person's body. The scent and strength of body odor is influenced by many things including diet, hygiene, gender, health, and certain medications. Body odor is typically associated with the underarms, groin, feet, genitals, pubic hair, and anus. These parts of the body contain apocrine sweat glands. Generally, human beings find most body odor to be an offensive smell, whereas other species, such as dogs, simply use body odor as a means to identify other animals.

What Causes Body Odor?

The human body has millions of sweat glands that secrete fluid to cool the body when its temperature rises. Perspiring, or sweating, is one of the human body's most natural and healthy responses. People perspire when they are hot, when they are exercising, and when they are nervous or uncomfortable. Adolescents, especially boys, tend to sweat quite a bit during puberty * . Perspiration is the body's built-in cooling system. In fact, two drops of sweat have the ability to cool up to one quart of blood by 1°F. However, sweat encourages the bacteria that are present on the skin to multiply. The more bacteria that are present on the skin, the greater the degree of body odor.

There are two types of sweat glands. Eccrine glands are present all over the body, and apocrine glands are present in areas where there are hair follicles, such as the groin, armpit, and scalp. Eccrine glands secrete fluid that is made up of water and salt directly onto the skin. The fluid that apocrine glands secrete, however, is made up of fats and proteins. These fats and proteins are broken down by bacteria on the skin. During puberty, apocrine glands become much more active, causing more body odor.


While perspiration does not have a smell on its own, the presence of sweat causes the bacteria that are normally present on the skin to multiply at a rapid rate. The increased amount of bacteria causes a person to have body odor. After activities that cause excessive sweating, such as working outside in the sun or engaging in strenuous exercise, people need to bathe with soap and water to remove the odor-producing bacteria. The use of deodorant and an antiperspirant is a helpful preventive measure.


Pheromones are chemicals released by the body that trigger a physiologic * response in another animal of the same species.

These responses can be positive or negative and may produce responses that are sexual, aggressive, or territorial in nature.

While pheromone stimulation is most noticeably present in other species, studies have shown that human beings also subconsciously respond to pheromones released by other humans. For instance, some studies suggest that the menstrual cycles * of women who are close to one another often synchronize. This may be mediated by pheromones. Other studies have shown that human beings tend to choose their mates based on the pheromones that he or she emits. While many scientists dispute this claim, some perfume and cologne companies even add pheromones to their products in the hopes of convincing people that it will help them attract a mate.

Health and Medication

Hyperhidrosis (hi-PER-hi-DRO-sis), or excessive sweating, is a medical condition with effects that may amplify a person's body odor. It can be caused by multiple conditions, including heredity; menopause * , which may cause hot flashes; hypoglycemia * , or low blood sugar; low levels of male hormones; and hypothyroidism * , or an underactive thyroid gland. Certain medications may also be the cause of excess sweating that leads to body odor. These include medications used to treat mental conditions, morphine, thyroxine, and analgesics such as aspirin.

In some cases, trauma may cause conditions that contribute to body odor. Rectovaginal fistulas are abnormal passageways between the rectum * and the vagina * . These fistulas can occur during childbirth or develop from conditions such as inflammatory bowel disease and infections. When this occurs, gas or stool may exit the body through the vagina, and sometimes fecal incontinence * may occur. This condition must be repaired surgically.

Social Issues and Treatment

People who have hyperhidrosis and body odor may suffer serious social consequences. These people often experience embarrassing body odor, wet marks or stains on clothes, and discomfort. Furthermore, they may have difficulty in school, work, social, business, and romantic situations. While proper hygiene is essential in preventing body odor, it sometimes cannot be controlled through bathing and the use of over-the-counter deodorants and antiperspirants. People who suffer from severe hyperhidrosis should talk to their doctor and pursue another treatment plan, which may include prescription antiperspirants, the use of nerve blockers that can prevent perspiration, medications, and in some cases, surgery.

See also Hypoglycemia • Incontinence • Menopause • Menstruation and Menstrual Disorders • Thyroid Disease


Books and Articles

Bodman, Susannah L. “Stench of Body Odor May Have Its Origins in a Bacterial Gene.” Oregonian, March 30, 2015. Available at: (accessed November 22, 2015).

Burningham, Sarah O'Leary. Girl to Girl: Honest Talk about Growing Up and Your Changing Body. San Francisco: Chronicle Books, 2013.


International Hyperhidrosis Society. “What Would Dry Mean to You?” . (accessed November 22, 2015).

Women's and Children's Health Network. “Hygiene.” Child and Youth Health. (accessed November 22, 2015).


American Academy of Pediatrics. 141 NW Point Blvd., Elk Grove Village, IL 60007-1098. Telephone: 847-434-4000. Website: (accessed November 22, 2015).

* bacteria (bak-TEER-ee-uh) are single-celled microorganisms, which typically reproduce by cell division. Some, but not all, types of bacteria can cause disease in humans. Many types can live in the body without causing harm.

* puberty (PU-ber-tee) is the period during which sexual maturity is attained.

* physiologic (fiz-ee-o-LOJ-ik) refers to an organism's healthy and normal functioning.

* menstrual cycle (MEN-stroo-al SY-kul) culminates in menstruation (men-stroo-AY-shun), the discharging through the vagina of blood, secretions, and tissue debris from the uterus that recurs at approximately monthly intervals in females of reproductive age.

* menopause (MEN-o-pawz) is the cessation of menstruation.

* hypoglycemia (hi-po-gly-SEEmee- uh) is a condition that occurs when the amount of glucose, or sugar, in the blood becomes too low. Symptoms can include dizziness, trembling, sweating, and confusion.

* hypothyroidism (hi-po-THY-roydih- zum) is an impairment of the functioning of the thyroid gland that causes too little thyroid hormone to be produced by the body. Symptoms of hypothyroidism can include tiredness, paleness, dry skin, and in children, delayed growth and mental and sexual development.

* rectum is the final portion of the large intestine, connecting the colon to the outside opening of the anus.

* vagina (vah-JY-nah) is the canal, or passageway, in a woman that leads from the uterus to the outside of the body.

* incontinence (in-KON-ti-nens) is loss of control of urination or bowel movement.

* toxins are substances that cause harm to the body.

Disclaimer:   This information is not a tool for self-diagnosis or a substitute for professional care.

(MLA 8th Edition)