Belly button infections
Like other parts of the body, the belly button can gather bacteria or fungi over time. This may trigger an infection, creating a funky smell in your belly button. People who have an “innie” belly button or a pierced navel may develop these infections more easily. Making sure your belly button is clean will help prevent any unpleasant smells and keep it healthy.
Belly button cysts
Cysts are liquid- or pus-filled growths that may feel hard or soft. If a cyst becomes infected, it can cause fluid to leak from the belly button. There are different types of cysts depending on what led to their formation.
Newborns and older kids can develop urachal cysts. The urachus is the tube that connects the fetal bladder to the umbilical cord. Although the urachus usually closes before a baby is born, sometimes it fails to seal completely. In this case, a cyst may form on it later in life. Other symptoms may occur, such as abdominal pain, a fever, and pain when urinating.
Other types of cysts — sebaceous (from sebaceous glands), epidermoid (from surface skin cells), and pilar (from hair follicle) — can also result in belly button discharge. If you think you may have a cyst, never try to burst it on your own. Instead, seek advice from a health care provider.
Poor hygiene
One of the most common causes of belly button odor is poor hygiene. The belly button can trap sweat, dead skin, and dirt. Many people forget to wash their belly buttons regularly, so germs tend to develop there. To keep a clean and healthy belly button, maintaining your overall hygiene is important.
Your skin houses trillions of bacteria that naturally develop and are usually harmless. The belly button’s folds of skin give the bacteria a great environment in which to grow. Bacteria have no odor, but if they get too densely packed, the decomposition of waste products can create a specific belly button smell.