Bromhidrosis Explained: Causes, Symptoms & Treatment

Struggling with persistent body odor, even with good hygiene? You might be dealing with bromhidrosis, a condition where sweat mixes with bacteria on the skin, creating an unpleasant smell. Unlike regular body odor, bromhidrosis is stronger, long-lasting, and often hard to control with basic deodorants.

The good news? There are effective ways to manage and treat it, from simple lifestyle changes to advanced medical solutions. In this guide, we’ll break down the causes, symptoms, and best treatment options—so you can feel fresher and more confident every day.

What Is Bromhidrosis?

Bromhidrosis is a medical condition characterized by an abnormally offensive body odor (B.O) that often reminds of onions or sulfur. The odor results from the interaction between sweat and skin bacteria, particularly when sweat contains high levels of lipids and proteins.

The smell of bromhidrosis can vary depending on factors like diet, hygiene, and the bacteria present on the skin. However, it’s generally described as:

Pungent and musky: A strong, lingering odor that doesn’t go away easily.
Cheesy or sour: Similar to the smell of aged cheese or fermented foods due to the breakdown of sweat proteins by bacteria.
Onion-like or garlicky – Especially if certain foods are a contributing factor.
Fecal or sulfuric: In severe cases, the odor can resemble rotten eggs or even a fecal-like smell due to specific bacterial activity.
Sweaty and ammonia-like: Some people describe it as a mix of strong sweat and ammonia, particularly when the body is breaking down proteins for energy.

Because the intensity and character of the odor depend on individual body chemistry and hygiene habits, some people may experience a milder scent while others struggle with a more overpowering smell.

There are two types of bromhidrosis: apocrine and eccrine.

Apocrine Bromhidrosis

Apocrine bromhidrosis is the most common type of bromhidrosis and is linked to sweat from the apocrine glands. These sweat glands are located in the armpits and genital area, becoming active during puberty.

Unlike the watery sweat from eccrine glands (which help regulate body temperature), apocrine sweat is thicker and contains proteins and lipids. On its own, this sweat doesn’t smell—but when bacteria on the skin break it down, it can create a strong, persistent odor.

In other words, when you have apocrine bromhidrosis, B.O. is the byproduct of lipid-rich sweat mixing with skin bacteria. When these two come together, they produce thioalcohols—compounds that smell like sulfur, onions or raw meat.

So, if your armpit sweat smells like onions, cheese or garlic, it may be a sign of apocrine bromhidrosis.

Eccrine Bromhidrosis

Eccrine bromhidrosis is the rarer form of bromhidrosis. Eccrine sweat glands are found all over the body, including the palms and soles, as well as the head or torso. Unlike apocrine sweat (which is thick and protein-rich), eccrine sweat is mostly water and salt, so it doesn’t naturally have a strong smell.

However, when it mixes with bacteria, environmental factors, or metabolic waste, it can develop an unpleasant odor. It happens when sweat from your eccrine glands softens the keratin on your skin. The softer the keratin is, the easier it is for bacteria to break down. This break-down process produces a stenchy odor, such as:

Ammonia-like: Common in people who eat high-protein diets or have metabolic disorders.
Vinegar or sour-smelling: Often linked to bacterial or fungal growth.
Sweaty and stale: A general musty smell from prolonged dampness.

Eccrine bromhidrosis is often easier to manage than apocrine bromhidrosis, but if odor persists despite good hygiene, it may be worth seeing a doctor to rule out underlying health issues.

What Causes Bromhidrosis?

While everyone produces sweat, not everyone experiences bromhidrosis—certain factors make some people more prone to it. We’ve already covered the differences between apocrine and eccrine sweat, so let’s focus on what else can contribute to this condition.

Genetics

Chronic B.O. can run in the family. Studies show that there is a strong correlation between the ABCC11 gene and bromhidrosis. This same gene is present in individuals with wet ear wax. So, believe it or not, if you have wet ear wax, you’re more likely to have bromhidrosis.

Obesity

Having large amounts of excess fat on your body makes you more susceptible to bromhidrosis.

Excess fat creates skin folds, and these warm, dark crevices are the perfect environment for sweat and bacteria to mix and produce an odor. Because these areas can be challenging to clean, you may neglect them when you bathe or shower. Failing to cleanse and exfoliate these areas allows bacteria and sweat to fester and create a pervasive odor.

Diabetes

Sometimes, bromhidrosis can be mistaken for a condition called diabetic ketoacidosis, which can occur if you have untreated diabetes. When you have diabetes, your body doesn’t produce enough insulin to regulate your metabolism. As a result, you start to break down fat which causes acids to build up in your bloodstream. This process can result in B.O. and bad breath.

Intertrigo

Intertrigo is a rash caused by trapped moisture and sweat. Although the most common form of intertrigo is infant diaper rash, adults can also get it from lack of air circulation to their skin.

When intertrigo goes untreated, bacteria thrive in moist, friction-prone areas which can lead to chronic B.O.

Erythrasma

Erythrasma is a bacterial infection caused by humid, tropical climates that manifests as a pink skin rash. The bacteria that causes this rash, Corynebacterium, naturally occurs on your skin. It’s also one of the bacteria that exists in excess for those with chronic B.O.

Hyperhidrosis

Bacteria and sweat are key components of bromhidrosis. So, if you suffer from hyperhidrosis or excessive sweating, you’re more likely to have chronic B.O. as well. If you think sweat or hyperhidrosis is contributing to your bromhidrosis, it’s best to treat hyperhidrosis first to reduce the sweat that’s affecting your B.O. issue.

Diet & Metabolism

What you eat can influence how your sweat smells. Certain foods contain sulfuric or pungent compounds that can make B.O. worse, including:

Garlic and onions: High in sulfur, which can lead to a stronger smell.
Red meat: Harder to digest, sometimes causing a more pungent odor.
Spicy foods and alcohol: Can trigger excessive sweating, leading to more odor.
Caffeine: Stimulates sweat production, making odor more noticeable.

Certain medications can also contribute to bromhidrosis by increasing sweat production, altering metabolism, or affecting the body’s chemical balance. Common culprits include:

Antidepressants and psychiatric drugs: Some SSRIs and antipsychotics can trigger excessive sweating.
Pain relievers (NSAIDs and opioids): May lead to increased sweat and odor changes.
Hormonal medications: Birth control, HRT, and testosterone therapy can alter sweat composition.
Diabetes medications and insulin: Can cause a fruity or acetone-like sweat odor.
Chemotherapy drugs: May change metabolism, leading to unusual B.O.
Antibiotics and antifungals: Can temporarily shift skin microbiota and sweat scent.
Blood pressure, thyroid, and steroid medications: Often linked to excessive sweating, worsening odor.

If you notice a change in B.O. after starting a medication, talk to your doctor about possible alternatives. Good hygiene and moisture-wicking fabrics can help manage symptoms.

Bromhidrosis vs. Regular Body Odor

Bromhidrosis differs from regular B.O. in intensity, persistence, and underlying causes:

It’s easy to keep natural B.O. under control with good hygiene habits and over-the-counter treatments like antiperspirant and deodorant. But when you have bromhidrosis, these simple solutions don’t work.

Here’s a breakdown between normal B.O. and bromhidrosis:

Common Signs & Symptoms of Bromhidrosis

If you’re wondering why you smell like onions or cheese, there’s a good chance you have bromhidrosis. Most of the time, you can detect bromhidrosis from its distinct scent. Common symptoms of this condition include:

Constant (but not overpowering) B.O.
B.O. within 30 minutes of showering or bathing
A cheese or meat-like smell coming from your underarms or groin
A garlic or onion-like smell coming from your breasts, underarms or groin
Social anxiety due to B.O.

Doctors can diagnose bromhidrosis by swabbing and testing the bacteria on your skin.

Excessive amounts of Corynebacterium, Propionibacterium, Staphylococcus and Micrococcus usually indicate chronic B.O. Staphylococcus is typically the strongest-smelling bacteria.

Being able to spot the signs of bromhidrosis is a helpful first step in overcoming chronic B.O. But to solve the problem, you also need to understand the underlying cause of your condition.

Bromhidrosis, whether caused by the apocrine or eccrine glands, is marked by a few distinct signs and symptoms that make it easy to identify. While B.O. is something most people experience from time to time, bromhidrosis refers to a persistent, often stronger-than-usual odor that doesn’t go away easily. Here’s what to look out for:

Persistent, Strong Odor

The most noticeable symptom of bromhidrosis is a strong, persistent B.O. that doesn’t improve with regular hygiene practices like showering and using deodorant. This odor is often described as musky, sour, or even ammonia-like, depending on the type of bromhidrosis (apocrine or eccrine).

Odor Concentrated in Specific Areas

While you may experience B.O. in various parts of your body, bromhidrosis tends to concentrate in specific areas, especially where you have high concentrations of sweat glands. The most affected areas include:

Armpits (axillary bromhidrosis): The most common area affected by bromhidrosis. Smell is typically strong, musky, or sour.
Feet (plantar bromhidrosis): Eccrine glands on the soles of the feet produce sweat that, when trapped in shoes and socks, creates a moist environment for bacterial and fungal growth, leading to a strong odor. Smell is often described as smelly cheese or rotten feet.
Groin and genital area: Apocrine glands in this region produce sweat that mixes with bacteria, dead skin, and moisture, causing a strong musky odor.
Underbreasts and skin folds: In people with excess body weight or larger breasts, sweat accumulates in skin folds, leading to bacterial and fungal growth that worsens odor. The smell is often yeasty or sour. Fungal infections, like yeast, can also contribute to the odor.
Scalp: Excessive sweating on the scalp, combined with oil production and bacterial activity, can create an unpleasant smell.
Hands and palms: Though less common, excessive eccrine sweating on the palms can create a noticeable odor, especially when in contact with certain materials or objects.

Worsening Symptoms With Heat or Stress

Heat, physical activity, or stress can trigger more sweat production, which, in turn, may worsen the odor. For people with bromhidrosis, the odor can intensify during hot weather or stressful situations when sweat levels increase, allowing bacteria to thrive.

Not Responding to Regular Deodorants

If you've tried different deodorants and antiperspirants but the smell still persists, it could be a sign of bromhidrosis. Standard deodorants might not be enough to manage the strong odor caused by bacterial breakdown of sweat, and stronger, prescription-strength solutions may be needed.

Increased Sweating

In some cases, bromhidrosis is linked with hyperhidrosis, a condition where the body sweats excessively. This extra moisture provides more opportunity for bacteria to break down sweat and create unpleasant smells.

If you notice any of these symptoms regularly, especially if they interfere with your daily activities or confidence, it might be time to seek treatment options or consult a healthcare professional.

Bromhidrosis Treatments

Thankfully, bromhidrosis is treatable. Here are some ways to mitigate excessive B.O. and stop smelling like onions:

Upgrade Your Hygiene Routine

Good hygiene is the first step in keeping B.O. under control. If regular washing isn’t enough, here are a few ways to keep the bacteria on your skin to a healthy minimum:

Use antibacterial or germicidal soap: Choose gentle liquid or cream body wash over solid soap, and avoid scented products that can worsen your B.O.
Shave excess body hair: Hair traps bacteria and sweat, which aggravates bromhidrosis.
Remove or wash sweaty clothes immediately: This gives bacteria less time to break down sweat.
Take regular warm baths or showers: Warm water can help kill the bacteria on your skin. Shower twice a day and pay close attention to extra sweaty areas, especially on a hot day.
Use extra-strength or prescription deodorant: Over-the-counter products might not cut it. Consult your doctor or dermatologist to explore prescription-strength deodorants and solutions.
Exfoliate regularly: Removing dead skin can reduce bacteria buildup.
Dry off completely: Damp skin creates the perfect environment for bacteria to thrive.

Wear the Right Garments

What you wear matters. Certain fabrics trap moisture and bacteria, making bromhidrosis worse, while others help keep you dry and fresh. Here’s how to choose the right clothing:

Cotton, bamboo, or moisture-wicking synthetic fabrics to keep sweat from lingering on your skin.
Loose-fitting clothes to allow airflow and prevent overheating.
Fresh socks and moisture-wicking shoes to combat foot odor.

If regular fabric isn’t cutting it, anti-odor clothing can be a game-changer. These garments are designed to minimize sweat and bacterial growth using advanced materials and treatments. Some great options include:

Thompson Tee’s Premium Anti Odor Shirt: Featuring an advanced Odor Shield™ technology, these shirts are made with hydrogen peroxide to neutralize skin bacteria, eliminating 99.9% of B.O..
Merino wool shirts: Naturally antibacterial and moisture-wicking, great for everyday wear.
Silver-infused or copper-infused clothing: These fabrics contain antimicrobial properties that kill odor-causing bacteria on contact.

Last but not least, keep your clothes fresh:

Wash sweaty clothes ASAP: Letting sweat sit in fabrics allows bacteria to multiply.
Use antibacterial detergent: Special detergents help break down sweat residue and bacteria.
Air-dry in sunlight: UV rays naturally kill bacteria and deodorize fabric.

Watch Your Diet

Avoid foods that promote pungent, odiferous sweat secretions to reduce the effects of chronic B.O. Try these odor-fighting foods instead:

Lemons, oranges and grapefruits
Green leafy vegetables like kale and spinach
Fresh herbs
Whole grains

Staying hydrated and eating a balanced diet can help your body flush out odor-causing toxins more efficiently.

Medical Treatments for Severe Cases

If lifestyle changes and over-the-counter solutions aren’t enough to control bromhidrosis, medical treatments can offer long-term relief. These options target either sweat production (to reduce the source of odor) or bacteria (to prevent sweat from breaking down into smelly compounds).

Topical or oral antibiotics: Topical antibiotics work by destroying odor-causing bacteria on the skin before they have a chance to break down and release a foul stench. Two common topical antibiotics for bromhidrosis are clindamycin and erythromycin. Oral antibiotics are used in more severe cases where topical solutions aren’t effective.
Laser and microwave therapy: For those who want a more long-term solution, laser and microwave treatments work by permanently disabling sweat glands in targeted areas.
Surgery (last-resort option): For extreme cases of bromhidrosis that don’t respond to any other treatments, surgical options may be considered: Liposuction or curettage of sweat glands or sympathectomy (nerve-cutting surgery). Both are highly invasive and could result in very serious long-term side effects. Don't explore this option until you've exhausted all other non-invasive treatment methods.

When to Seek Medical Help

If bromhidrosis is persistent, severe, or affecting daily life, consult a dermatologist to explore the best treatment options. Relief is possible!

Fight Bromhidrosis With Anti Odor Shirts

Managing bromhidrosis doesn’t have to be a struggle. By combining the right hygiene practices, medical treatments, and odor-fighting clothing, you can take control of body odor and feel more confident every day.

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