What Causes Body Odor—and How Can You Reduce It?

Body odor develops when sweat mixes with the bacteria on your skin. Sometimes body odor is mild and even pleasant. Other times, the odor may be strong and unpleasant.

Even though everyone emits odors from their bodies, you may be looking for ways to manage the smell. This is in part because bad body odor can affect your self-esteem, relationships, and lifestyle.

You can make changes to improve the smell. Knowing a bit more about body odor and what causes it can help you reduce and prevent the odor, too.

What Is Body Odor?

Body odor is a scent that comes off your body that many people might consider to smell bad. Body odor is normal and is something everyone experiences. Body odor that is excessive or particularly pungent is medically known as bromhidrosis. Bromhidrosis is a term with Greek origins—bromos means stench, and hidros means sweat.

Body odor is not the smell of your sweat. Contrary to popular belief, sweat itself does not have a particular scent. Instead, body odor is the smell that's created when your sweat mixes with bacteria on the skin. Because bacteria thrive in areas that trap moisture and warmth, most body odor comes from under your arms. The feet, palms, and genital areas also emit body odor.

What Causes Body Odor?

Body odor can develop when bacteria and yeast that live on your skin mix with sweat. When the microorganisms and sweat mix, the bacteria and yeast break down the sweat. The decomposition process is what causes body odor.

Humans have two main types of sweat glands on their bodies: eccrine and apocrine glands. Both types of glands produce sweat that can lead to body odor.

Eccrine glands cover much of the body's surface and produce sweat to help regulate body temperature. People of any age can experience body odor from sweat produced by the eccrine glands. Typically, it is the soles of the feet where the body odor would be.

Apocrine glands are located in the armpits and genital area, as well as around the anus and nipples. Apocrine glands are the glands most closely associated with body odor. They have a higher sweat secretion rate than other sweat glands. Apocrine glands become active during puberty, which is why puberty is associated with increased body odor and why prepubescent children rarely produce noticeable body odor.

Body Odor Triggers

Everyone sweats and has some degree of body odor. Some factors might innately make you likelier to produce body odor. For instance, there are some indications that genetics may play a part in whether you are more likely to produce a strong body odor.

Your sex might also have an impact on body odor—men have larger sweat glands than women and tend to sweat more profusely, so men may be more prone to body odor than women.

There are also some situations and medical conditions that may cause you to have a stronger and more pungent body odor than other people.

Increased Sweating

You might have an increase in sweat production due to temperature, activity, or fever. While the sweat itself does not cause body odor, the extra sweat production does give more of an opportunity for sweat to mix with bacteria and lead to body odor.

Hormonal changes can also contribute to more sweating. Some menstruating people may notice they sweat more during certain times of their cycle, such as during the time between ovulation and the start of their period (the luteal phase).

Increased sweating is also common during menopause. Known as hot flashes, these bouts of sweating happen mostly at night and are associated with the shifts in hormones that happen after someone has stopped having their period.

An uptick in sweating can also occur soon after you’ve given birth, as your hormones fluctuate.

Sweating is also a common reaction to stress and panic. Increased sweating caused by stress occurs in the apocrine glands, located primarily in the armpits. Sweat from apocrine glands is what primarily results in body odor, which is why sweating caused by stress in particular produces an increase in body odor.

Excessive Sweating

Sweating a lot—even if you are in cooler weather or at rest—may be a sign of a condition called hyperhidrosis. Hyperhidrosis is caused by overactive sweat glands. When people with the condition sweat, they usually do so from one or two areas of the body, such as their armpits, head, feet, or palms.

While the sweat itself is odor-free, the larger volume of sweat in hyperhidrosis does give the body more opportunity to mix with bacteria and produce odor.

Diet

You might notice that if you eat certain foods, your sweat becomes more pungent. This is because you are taking in compounds that promote odor.

Onion and garlic are foods that are well-known for causing strong body odor. Powerful spices like curry may also contribute to a more noticeable body odor.

Alcohol can also trigger body odor.

Medical Issues

Although it’s normal to have body odor, some kinds of body odor may indicate an underlying medical condition. For example, liver disease and kidney disease may cause your body odor to smell like ammonia (bleach). A fruity-smelling body odor might be a sign of diabetes. A rare genetic disorder called trimethylaminuria may cause you to have a strong, fishy body odor.

With trimethylaminuria, the body can't break down trimethylamine, a chemical compound that has a foul odor. It might not just be your body odor that smells like fish, but also your urine and breath.

Like trimethylaminuria, other rare genetic conditions can affect your metabolism and cause abnormal body odor. These include:

• Phenylketonuria (PKU): PKU causes the protein phenylalanine to build up in the blood. People with PKU that has not been treated may have a musty or mouse-like odor. 
• Isovaleric acidemia: With this condition, your body can't properly break down an amino acid (protein building block) called leucine. If you have this condition and become ill, you might produce a body odor of sweaty feet.
• Hypermethioninemia: This condition causes a buildup of an amino acid called methionine since your body can't properly break it down. Your sweat, as well as your breath and urine, may smell like boiled cabbage.

Treatments for Body Odor

Most times, body odor can be managed with a few simple hygiene techniques.

Letting sweat sit on the skin for long periods of time will increase body odor. Therefore, changing out of wet clothes and bathing after physical activity or any other occasion you've sweated can help prevent body odor.

Regular showering can reduce your body odor, too, since it can wipe off the odor-causing bacteria and yeast from your skin. Using an antibacterial soap may be particularly helpful.

Keeping your body as dry as possible will help reduce body odor. Of course, this isn’t always possible, and this is where antiperspirants come into play. While deodorant can protect against odor, antiperspirant helps keep the skin dry by reducing sweating. Antiperspirant also mask the scent of body odor.

While these methods may be enough for most people, you might need further interventions if you have sweat excessively. For exaple:

• Iontophoresis, a no sweat-machine that uses electric currents that pass through water to shut down sweat glands
• Botox injections in your underarms, which block a chemical in your body that triggers sweat glands
• Prescription cloth wipes, which contain an ingredient called glypyrronium tosylate that can reduce sweating
• Prescription medications, which prevent sweat glands from working
• Surgery to remove sweat glands and certain nerves associated with sweating
• Hand-held medical devices that emit electromagnetic energy and destroy sweat glands

If something you ate is causing the body odor, the smell should soon go away. If the food or drink is a regular part of your diet, you can bathe regularly and use deodorant, perfume, or cologne to mask the smell.

If a medical condition is causing a change in body odor, treating the condition can help normalize your body odor. For instance, if diabetes is causing you to have fruity-smelling body odor, managing your blood sugar can help get rid of the smell.

How To Prevent Body Odor

While body odor can’t be prevented in all circumstances, there are things you can do to decrease the frequency and intensity of body odor. These include:

• Bathing regularly
• Bathing after exercise or physical exertion
• Changing your clothes frequently
• Wearing deodorant or antiperspirant
• Shaving your armpits because body hair can trap moisture, leading to more body odor
• Managing stress
• Reducing odor-causing foods from your diet
  

When To See a Healthcare Provider

Having body odor is a normal part of life and generally can be managed at home with proper hygiene techniques. But if you are unable to control your body odor and the odor is causing you emotional distress or is affecting your relationships, career, or social life, a healthcare provider may be able to give you the help you need.

Also see a healthcare provider if you sweat profusely even when not physically active, or if your body odor has a peculiar scent—such as smelling sweet, fishy, or like bleach. This may be indicative of a medical condition that needs attention.

A Quick Review

Everyone has body odor. Body odor is a normal human phenomenon that happens when the bacteria and yeast on your skin break down your sweat. The decomposition of the sweat causes a smell many people find unpleasant.

While body odor is nothing to be ashamed of, it doesn’t mean it doesn’t make you feel uncomfortable or embarrassed. While washing regularly and wearing deodorant are enough for many people to keep their body odor under control, these techniques aren’t always enough.

If you are experiencing excessive body odor or are having trouble managing your body odor, you might benefit from other techniques that a healthcare provider can talk to you about.