The Causes of Smells and Body Odor

Living with body odor can be extremely uncomfortable, embarrassing to discuss and frustrating to deal with. Smells and odors can be caused by a variety of factors, ranging from medications to medical conditions. If you're experiencing excessive body odor, consult your doctor.

Anaerobic Bacteria

Underarm odor is caused by perspiration. Sweating from exercise, hot weather, and anxiety can produce this perspiration. However, sweat is actually odorless. Bacteria on the skin flourish in moist areas lacking oxygen, known as anaerobic conditions. The result of this bacteria proliferation is the unpleasant underarm odor often referred to as B.O., or body odor.


As pre-teens enter puberty, hormones begin to surge. Sweat glands produce underarm moisture, which can begin to smell. Depending on the child, this change can begin as young as at 9 years old. As this occurs, you may want to provide your child with a deodorant and antiperspirant to decrease the odor. During menopause, high levels of estrogen lead to hot flashes and increased perspiration, precipitating odor.


Sweat accumulation on the bottom of the feet can lead to the production of yeast. Enclosed in socks and shoes, the yeast have the opportunity to multiply rapidly, intensifying the odor. Synthetic socks may also increase the growth of yeast. Smelly feet are common in locker rooms.


People with diabetes may give off a fruity or sweet smell from their breath. This smell is caused by a condition called ketoacidosis, which develops as a result of poor blood sugar management. The National Institutes of Health states that this occurs "as the body attempts to get rid of excess acetone through the breathing." This condition requires daily treatment and management 13.

Liver Disease

Patients with hepatic encephalopathy or liver disease may show signs of this disease with a strange odor on their breath 3. According to the National Institutes of Health (NIH), their breath may have a musty or sweet odor 13. NIH states that this and other symptoms may be mild at first and gradually worsen. Caregivers and family would likely notice this odor.


Body chemistry can play a part in your natural scent, including the odor you emit. For instance, you may smell of fish if your body cannot properly metabolize large quantities of protein. Strong flavors such as onions, garlic and curry can give off a strong body odor. Alcohol and coffee consumed in excess are also a primary cause of offensive odors.

Poor Hygiene

Sometimes body odor is simply caused by poor hygiene. Failure to bathe on a regular basis or adequately wash clothing can result in strong odors. Poor bathroom habits can increase body odor as well. Men with poor care of an uncircumcised penis, and women who do not properly wipe to prevent the introduction of bacteria, may have odors.


Occasionally medications -- including prescription, over-the-counter, herbs and vitamin supplements -- may cause a strange body odor. Typically, this is a less common side effect of medication, but it's a possibility, and one you should mention to your doctor if you notice an odor after starting a new drug. Topamax, a medication used for migraines, is one medication that may have a side effect of body odor, according to the Migraine Awareness Group 2.