Understanding Bromhidrosis: What is the smell of sweat called?

September 21, 2025 •

4 min read

Contrary to popular belief, sweat from your body's eccrine glands is actually odorless. The characteristic odor often associated with perspiration has a specific medical name and is caused by bacteria on the skin, not the sweat itself. Knowing exactly what is the smell of sweat called is the first step toward understanding this common biological process.

Quick Summary

The medical term for the smell of sweat is bromhidrosis, or osmidrosis, which occurs when skin bacteria break down the proteins and lipids in apocrine sweat, releasing volatile organic compounds.

Key Points

The Cause of Body Odor: The smell of sweat, or bromhidrosis, is caused by bacteria on the skin breaking down apocrine sweat, not the sweat itself.
Two Types of Sweat Glands: Eccrine glands produce mostly odorless, watery sweat for temperature regulation, while apocrine glands in hairy areas produce a thicker, protein-rich sweat that bacteria can feast on.
Volatile Compounds: The breakdown of apocrine sweat by bacteria, such as Corynebacterium, releases volatile organic compounds (VOCs) that are responsible for the distinct odor.
Bromhidrosis vs. Hyperhidrosis: While excessive sweating (hyperhidrosis) can worsen body odor, the two are distinct conditions. Bromhidrosis is specifically the odor, while hyperhidrosis is the excessive sweating.
Factors Affecting Odor: A person's body odor can be influenced by genetics, diet, hormonal changes, medications, and underlying medical conditions.
Management Strategies: Options for controlling body odor range from simple hygiene practices and over-the-counter products to more advanced medical treatments like Botox injections for severe cases.

The Science Behind the Odor: It's Not the Sweat Itself

To understand the root of body odor, one must look past the sweat itself. Normal human sweat is virtually odorless and is primarily composed of water and salt. The unpleasant smell develops when bacteria that live naturally on the skin's surface interact with and break down the secretions produced by certain sweat glands. This is a natural metabolic process and the intensity and nature of the resulting odor can vary significantly from person to person.

The Role of Apocrine and Eccrine Glands

Your body has two main types of sweat glands, each with a distinct purpose and secretion:

Eccrine Glands: These glands are distributed across most of your body and secrete a watery, clear, and mostly odorless sweat. Their primary function is to regulate body temperature through evaporation. The sweat from these glands, while typically not smelly, can become malodorous in certain medical conditions (known as eccrine bromhidrosis) or when bacteria degrade softened keratin on the skin's surface.
Apocrine Glands: Located predominantly in areas with a high density of hair follicles, such as the armpits, groin, and scalp. These glands become active during puberty and secrete a thicker, milky fluid rich in proteins and lipids. The fluid is initially odorless, but it is this nutrient-rich environment that provides food for skin bacteria, leading to the characteristic smell we associate with body odor.

The Bacterial Factor: A Metabolic Process

The smell of sweat, known medically as bromhidrosis or osmidrosis, is a direct result of bacterial activity. The skin's microbiome, the community of microorganisms living on its surface, varies from person to person. Specific bacteria, notably from the Corynebacterium and Staphylococcus genera, are key players in breaking down apocrine sweat. The products of this metabolic process are volatile organic compounds (VOCs) that give sweat its potent smell. Some examples of these compounds include:

3-methyl-2-hexenoic acid (3M2H): Described as having a 'goat-like' smell.
3-methyl-3-sulfanylhexan-1-ol (3M3SH): An onion-like or meaty smelling thioalcohol.
Isovaleric acid: A cheesy-smelling compound produced by bacteria on the feet.

Factors Influencing Body Odor

Beyond the natural process of bacterial breakdown, several factors can influence the intensity and type of body odor a person experiences:

Genetics: An individual's genetic makeup, including the ABCC11 gene, can affect the composition of their sweat and their predisposition to body odor.
Diet: The saying "you are what you eat" holds some truth for body odor. Foods rich in sulfur compounds, such as garlic, onions, and certain vegetables, can be excreted through sweat and breath, contributing to odor.
Hormonal Changes: Puberty, menopause, and menstruation involve hormonal shifts that can affect sweat production and body odor.
Underlying Medical Conditions: Certain systemic diseases, like liver or kidney disease and diabetes, can cause changes in body odor due to the excretion of metabolic byproducts.
Medications: Some drugs, including certain antidepressants and antibiotics, can alter body odor.

Bromhidrosis vs. Hyperhidrosis

It's important to distinguish between two sweat-related conditions that are often conflated:

Bromhidrosis: The condition defined by offensive body odor.
Hyperhidrosis: A condition of excessive sweating.

While excessive sweating (hyperhidrosis) can create a moister environment that encourages bacterial growth and thus worsens bromhidrosis, they are not the same condition. A person can have one without the other, although they often coexist. Treatment for one may not fully resolve the other.

Managing Body Odor and Bromhidrosis

For most people, good personal hygiene is enough to manage body odor. However, for those with clinical bromhidrosis, a more targeted approach may be necessary. Treatment strategies can be categorized into lifestyle adjustments and medical interventions.

Comparison of Body Odor Management Methods


Method	How It Works	Best For	Pros	Cons
Hygiene	Daily washing with antibacterial soap; regular cleaning of affected areas.	General body odor management.	Simple, inexpensive, and effective for most.	Requires consistency; may not be enough for severe cases.
Antiperspirants	Temporarily blocks sweat glands to reduce perspiration.	Reducing wetness and subsequent odor.	Effective for controlling sweat; widely available.	Can cause skin irritation; some concern over ingredients.
Deodorants	Masks odor with fragrance and/or uses antimicrobials to reduce odor-causing bacteria.	Masking and reducing odor.	Variety of scents available; targets the odor directly.	Does not stop sweating; some ingredients may irritate skin.
Hair Removal	Shaving or waxing reduces the surface area for bacteria to grow and traps less moisture.	Reducing odor in high-hair areas like armpits.	Simple and can be effective.	Temporary; risk of irritation from removal method.
Dietary Changes	Limiting or avoiding foods known to cause strong body odor.	Individuals who notice a link between diet and odor.	Natural approach with added health benefits.	Results may be minimal or vary greatly.
Botox Injections	Blocks nerve signals to sweat glands, reducing sweat production.	Severe hyperhidrosis and bromhidrosis.	Highly effective and long-lasting (several months).	Invasive, expensive, and not a permanent solution.

For more information on the intricate relationship between skin microbiota and malodor, you can explore research from the National Institutes of Health. https://pmc.ncbi.nlm.nih.gov/articles/PMC7215946/

Conclusion

Ultimately, understanding the true cause of body odor is key to effectively managing it. The process is a fascinating interplay between our body's secretions and the microscopic world living on our skin. While bromhidrosis is a normal biological occurrence, it can be a source of significant distress for some. By addressing the root causes, from hygiene habits to underlying health concerns, individuals can take control of their body odor and improve their quality of life. Whether through simple lifestyle changes or medical intervention, there are practical and effective solutions available.

Frequently Asked Questions

Sweat from the eccrine glands, which are found across most of the body, is mainly composed of water and salt. This mixture is sterile and odorless when secreted. The smell only develops when bacteria on the skin consume the nutrients in apocrine sweat.

While bromhidrosis is a normal biological phenomenon, it can become a distressing medical condition if the odor is excessive and negatively impacts an individual's quality of life. It can typically be managed with hygiene and topical treatments, but severe cases may warrant medical attention.

Yes, certain foods, particularly those rich in sulfur compounds like garlic, onions, and some spices, can be metabolized and their byproducts excreted through sweat, leading to a noticeable change in body odor.

To prevent odor from sticking to clothes, wear breathable, natural fabrics like cotton, as synthetic materials can trap moisture and odor. Using an antibacterial laundry detergent and washing clothes promptly after exercise can also help.

Deodorants work by masking or neutralizing odor and killing some bacteria, while antiperspirants block sweat glands to reduce wetness. For managing the smell of sweat, a combination product or an antiperspirant to control the wetness and reduce bacterial proliferation is often most effective.

Yes. Some underlying health conditions can cause sweat to have a specific, unusual smell. For example, diabetes can cause a fruity odor, while liver or kidney problems might produce a bleach-like smell due to the body excreting toxins through sweat.

During puberty, the apocrine sweat glands become active for the first time. The hormone-driven production of their nutrient-rich sweat creates a new food source for skin bacteria, which in turn leads to the production of noticeable body odor.