Belly button odor is more common than some realize, and it can result from basic hygiene issues as well as more serious infections.
1. Poor Hygiene
Washing with soap and water helps remove dirt, oils, and sweat from your skin. But without regular cleansing, these substances can build up in the navel, potentially leading to a musty odor.
This is especially true if you have a deeper-set belly button because the extra folds of skin can make thorough cleaning more challenging, explains Barbara Bawer, MD, a family medicine physician at Ohio State University Wexner Medical Center in Columbus, Ohio. “A deeper-set belly button creates a darker, more humid environment where bacteria can thrive,” she says.
2. Accumulation of Dirt, Sweat, Lint, or Debris
Even if you shower or bathe regularly, your belly button might not get the attention it needs. This often-overlooked area also acts as a catchall for dead skin cells and lint from clothing. And between trapped moisture and accumulated debris, it’s an ideal environment for odor to develop.
This combination also creates the perfect condition for a navel stone to form. This is a small, painless mass made from clumps of debris that can have an unpleasant odor, too.
3. Bacterial Infections
While it’s normal to have some bacteria on the skin, problems can occur when bacteria gets inside the belly button and multiplies. Bacterial infections that may affect the belly button include impetigo (which often starts as sores or blisters on the mouth and nose) and cellulitis (which often causes swelling and pain), and these typically occur when skin bacteria enters the skin through a cut and multiplies, according to Dr. Bawer.
If you don’t completely dry the navel after bathing or sweating, moisture can encourage the growth of bacteria that cause impetigo and cellulitis. Signs of an infection in your belly button include swelling, redness, pain, pus, and a foul smell coming from the affected area.
These infections are more likely in individuals with a weakened immune system (often caused by chronic diseases like diabetes, cancer, and HIV/AIDS), poor circulation, skin folds due to overweight and obesity, and lack of mobility due to illness or injury. These factors can impair healing, which creates an environment for bacteria to thrive.
Bacterial skin infections are usually mild and treatable with antibiotics. However, if left untreated they can lead to complications like abscesses (pockets of pus that may require drainage) or sepsis (a life-threatening infection that spreads to the bloodstream).
4. Yeast Infections
Yeast infections — which can cause a sour, bread-like odor — can also occur in the navel. A common culprit is Candida, says Bawer. This fungus thrives in dark, warm, and moist environments, making the belly button an ideal spot, she explains.
Sweating heavily, such as during workouts or in hot, humid climates, can increase moisture in the belly button. Additionally, wearing tight clothing or fabrics that don’t breathe well can trap heat and moisture, creating a breeding ground for fungi.
Individuals who take antibiotics, wear dentures, are getting cancer treatment, or have health conditions that affect the immune system (like HIV or diabetes) are also at greater risk of yeast infections.
Belly button yeast infections often improve within a couple of weeks of starting treatment with a topical antifungal cream, ointment, or powder. However, infections can return if the area isn’t kept dry.
5. Cysts
A buildup of dead skin cells and oils in the belly button can also cause small, nonpainful bumps beneath the skin called epidermoid cysts. While these cysts are typically harmless, they can become infected or inflamed. When this happens, you might notice a grayish-white discharge and a cheesy odor.
If left untreated, a cyst can become infected, leading to the development of an abscess that may require drainage.
6. Piercings
Another worrisome cause of belly button odor is an infection, either in the belly button itself or spreading through the body, often caused by not cleaning a belly button piercing regularly with warm soap and water, says Benedict Ifedi, MD, a family medicine physician with Memorial Hermann in Houston, Texas.
If a belly button piercing is not properly cleaned, dead skin cells, oils, and bacteria build up, leading to infection. Common symptoms of infection include pain, redness, and smelly pus that can be yellow, gray, green, brown, white, or blood-red.
Similar to other infections, if a belly button infection from a piercing is left untreated, the bacteria can multiply and spread beyond the piercing site, potentially entering the bloodstream. This can lead to sepsis.