Body odor does not result directly from sweat but from bacterial processes that occur within it. Taking steps to stop sweat accumulating can help manage and prevent body odor.

It is a common misconception that sweat itself causes body odor. In actual fact, human sweat is almost odorless.

Body odor occurs due to bacteria on a person’s skin breaking down protein molecules within sweat and producing odor as a result.

Body odor is a common problem, but it can severely affect a person’s quality of life. Although its root causes are often down to a person’s hygiene practices, body odor can indicate a more serious underlying condition in some instances.

The body can produce odors in the mouth and other cavities, as well as in bodily fluids. However, this article focuses on odors originating from a person’s skin and the bacterial processes in sweat.

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Body odor is an umbrella term for natural smells originating from a person.

The human body can produce a range of substances that carry a smell, known as odorants. Many of these are important for regular bodily function and, in small quantities, do not lead to unpleasant odors. However, an excessive accumulation of these compounds on the skin can cause noticeable smells.

Body odor usually becomes more evident during puberty, as hormones and sweat glands become more active at this time. People with obesity and individuals with certain medical conditions, such as diabetes, are also more susceptible to having body odor.

Sweat itself is virtually odorless to humans. However, the rapid multiplication of bacteria and their breaking down of sweat into acids can cause unpleasant smells. As a result, people who sweat a lot — such as those with hyperhidrosis — may be more susceptible to developing body odor.

Body odor is most likely to occur in the following places:

  • the feet
  • the groin
  • the armpits
  • the genitals
  • pubic and other hair
  • the belly button
  • the anus
  • behind the ears

A person’s diet, natal sex, health conditions, and medications help create a unique body odor. Some research suggests that people, and moreso animals, are adept at identifying individuals by these smell profiles.

A person’s skin contains both eccrine and apocrine sweat glands.

Apocrine glands start to function at puberty and are associated with hair follicles in the underarms and groin. These glands produce a viscous, protein-rich sweat that is initially odorless. However, as bacteria break down the abundance of proteins, they will produce odorant molecules in greater concentrations, causing body odor.

In contrast, eccrine sweat glands predominantly regulate body temperature through perspiration and are not as strongly linked with body odor.

Having a large concentration of apocrine glands in the armpits and groin makes these areas susceptible to the rapid development of body odor. However, body odor can occur almost anywhere on a person’s body.

Although there is no universal treatment for the causes of body odor, taking the following steps may help control body odor:

  • Washing: A person should wash regularly with soap and ensure that they dry themselves thoroughly.
  • Shaving: Having hair in areas such as the armpits can slow down the evaporation of sweat, giving bacteria more time to break down proteins and create odorants. Shaving can help body odor control in that area.
  • Using antiperspirants: Antiperspirants can reduce the intensity of a person’s body odor by changing sweat volumes and altering the amount and activity of odor-causing bacteria.

A person may also experience noticeable body odors in areas that are often covered by clothes, such as the feet. A combination of increased humidity and sweat trapped in the fabric can promote bacterial multiplication and activity. This can lead to body odor.

To prevent this, a person may wish to pay extra attention to these areas when washing and ensure that they are completely dry before putting on clean clothes. Wearing natural fibers may also help with the evaporation of sweat and help reduce bacteria buildup.

Consuming chilies, onions, garlic, and other potent foods can also make some people’s sweat more pungent. If a person consumes excessive amounts of protein, this may also affect their body odor.

If body odor is affecting a person’s quality of life and home remedies have not worked, a doctor may recommend additional treatments. These may include:

  • Aluminum chloride: A doctor or dermatologist may recommend prescription antiperspirants containing aluminum chloride. Aluminum chloride is absorbed into the skin and reduces the amount a person sweats. Prescription antiperspirants can contain 10–30% aluminum chloride.
  • Botulinum toxin (Botox): A medical professional may recommend Botox treatment for people who sweat excessively. They may inject Botox directly into the skin, which can block the release of chemicals that trigger sweating. Some reports indicate that Botox injections in the armpits can reduce sweating by 82–87%.
  • Surgery: When self-care and medicinal measures are not effective at treating severe body odor, a doctor can perform a surgical procedure called an endoscopic thoracic sympathectomy (ETS). This severs the sweat-controlling nerves below the skin of the armpits. This option is a last resort, and it runs the risk of causing damage to other nerves and arteries in the area. However, a 2019 review found that more than 90% of people who underwent ETS reported improved quality of life after the procedure.

Some medical conditions may change how much a person sweats or the odor their body produces. These can be indicators of more serious conditions. If a person notices any of these changes, they should contact a doctor immediately.

For example, an overactive thyroid gland or menopause can make people sweat much more, while liver disease, kidney disease, and diabetes can change the consistency of sweat.

A person should contact a doctor if:

  • They start sweating at night.
  • Bouts of sweating occur irregularly or at excessive levels.
  • They begin to experience cold sweats.
  • Changes to their sweating are impacting their daily life.

A person should also contact a doctor if their body odor suddenly smells different. A fruity smell could indicate diabetes due to having high levels of ketones in the bloodstream, while liver or kidney disease can often lead to a bleach- or ammonia-like smell due to a buildup of toxins in the body.

Body odor is a common occurrence, and people can often remedy it at home. It is a byproduct of bacteria breaking down proteins in a person’s sweat and not due to the smell of sweat itself. Although people often associate body odor with unpleasant smells, this is not always the case.

Thoroughly washing, using antiperspirants, and shaving may all assist a person in managing unwanted body odor. If symptoms persist, a doctor may recommend prescription treatments and, in some cases, surgery.

Body odor and excessive sweating may also be indicators of an underlying health condition. If a person notices unexpected changes in their body odor or volume of sweat, they should consult a medical professional immediately.