Body odor is, by definition, an unpleasant body smell. It is the result of the interaction between sweat produced by sweat glands and oil produced by sebaceous glands and the bacteria that live in the ducts of the sweat and sebaceous glands and on the skin. While it is normal to have some degree of odor, anything too strong classifies as bad body odor, whether it’s an unpleasant smell or an agreeable, but too strong a scent. Body odor also changes with time so you might wake up one day to having a different smell from the one you were used to. Causes are diverse and range from hormonal changes such as those occurring in pregnancy or with age to dietary changes, side effects of medication or illness.
Body odor causes. Here are the top 11 causes of body odor and what they mean:
1) Age. Some degree of body odor is normal after a certain age and in certain age groups. Because of significant changes in endocrine function and metabolism occurring both in adolescents and the elderly, both age groups often develop a specific smell. In adolescents, there may be a more smelly sweat even with frequent washing and use of deodorant due to a surge in hormone production. The elderly have what is colloquially known as ‘old people smell’, presumably the result of a compound called nonenal, a by-product of the aging process. As we age, natural skin oils oxidize more quickly which leads to the formation of specific odor-giving compounds that result in the particular smell.
2) Hormonal changes. Hormones are responsible for the way we smell. For women, a drop in estrogen levels occurring during middle age can cause a certain degree of body odor. Hormonal changes are also the reason why some adolescents start sweating excessively or develop a heavy smelling sweat despite practicing good hygiene. A change in body odor can be a sign of pregnancy and is presumed to occur primarily due to fluctuating progesterone levels. However, pregnant women often report experiencing a heightened sense of smell which could explain the change in their own body odor perception. There are also reports of women experiencing a change in body odor since giving birth which could be explained by either fluctuations in hormone levels or an increase in smell sensitivity which makes them more perceptive to their own body smell.
3) Genetics. Some people have very little body odor. Others have quite a strong smelling sweat or a particular skin odor, not necessarily unpleasant, but simply more odorous. This has to do with genetic predispositions that determine reduced, normal or increased body odor and is part of the pool of genetic diversity. What determines normal body odor for different people is a set of proteins on the surface of cells known as major histocompatibility complex. This same set of genes also determines type of earwax.
If you find someone’s body odor disagreeable without it necessarily being unpleasant or a result of poor hygiene, it is likely because of their genetic makeup that may be too similar to yours. All of us are predisposed to choose partners with different genes in order to maintain diversity of the gene pool and have strong, resilient offspring. Adaptation to different climates also determines the number of sweat glands and, consequently, amount of sweat produced and body odor.
4) Sweating too much. Excessive sweating can occur because of intense physical exercise, high temperatures or medical conditions such as hyperhidrosis which causes too much sweating in general and predisposes to bad smells. Whatever the reason, good hygiene can help prevent and remedy bad body odor.
5) Poor hygiene. One of the main causes of body odor is poor hygiene. Not washing as often as needed causes oils from sebaceous glands to accumulate and offer a plentiful source of food for bacteria that are normally found on the skin. This causes excessive growth of bacteria populations and predisposes to bad body odor.
6) Trimethylaminuria (fish odor syndrome). It is a metabolic condition in which gut bacteria synthesize too much of a compound called trimethylamine. The compound is released in sweat and other fluids as well as with exhalation. It results in a strong fish-like odor and bad breath, hence the name fish odor syndrome. High-protein foods rich in choline, carnitine and lecithin all cause and worsen the condition.
7) Bromhidrosis is a condition that affects sweat glands and causes excess sweating. The excess perspiration is then metabolized by bacteria found naturally on the skin, resulting in various odors such as sour, rancid, musty, ammonia or pungent smells.
8) Other conditions, infection and diseases. Diabetes is known to cause bouts of excessive sweating from low blood sugar levels. Hyperthyroidism is a condition that causes sensitivity to heat and excess sweating. Both increase the chances of body odor. Skin fungal infections such as athlete’s foot or fungal infections of the scalp cause localized bad odor. Pituitary gland problems, gout, tumors and cancer, kidney disease, liver disease or anxiety can all indirectly cause body odor through increased sweating. For example, diabetes can cause a sweet, fruity smell, while liver diseases can cause an ammonia like, bitter or maple syrup odor.
9) Medication. Antipyretics used to reduce fever (example: paracetamol), antidepressants, anxiety and anti-inflammatory medication, anticholigernic medication for vertigo, motion sickness, digestive disorders, chronic respiratory conditions and others can cause excess sweating and body odor.
10) Diet and lifestyle. Being overweight, smoking and wearing clothes that are too thick, too tight or made from synthetic fabrics, drinking coffee, alcohol, soft drinks, eating fried foods, red meat, high-protein and processed foods all contribute to bad body odor either directly or indirectly by accentuating symptoms of existing conditions. Spices like hot peppers, wasabi or horseradish raise body temperature and cause sweating, contributing to body odor. Garlic, onions or cabbage family vegetables, fish, eggs, especially duck and goose eggs which are high in choline are some other foods that cause body odor (see article on Garlic Body Smell).
11) Other causes include magnesium deficiency, tooth decay and gum disease for bad breath, peptic ulcers, intestinal parasites, stress, not eating enough fruits, sharing personal objects or walking barefoot.
Having some degree of body odor is natural at all ages, but if that odor is too noticeable to those around you or it starts upsetting you, then it’s safe to say it’s not normal and you should do something about it. Similarly, if you experience excessive sweating and it’s never happened to you before, make an appointment with your doctor as soon as possible to identify the cause. This being said, below are some great remedies and treatment options.
How to have less body odor.
1) Shower as often as you need to, especially after exercising, being in hot weather and after any activity that causes you to sweat a lot. Brush teeth after every main meal and use mouthwash with antibacterial action.
2) Use zinc-based or other antiseptic washes to help keep bacteria numbers down and prevent bad smells. For bad scalp smell, get a special antibacterial hair wash from the pharmacy.
3) Wash underarms with antibacterial soap or body wash and apply antiperspirants. Repeat the process several times a day to counteract bad smells.
4) Wear clothes made from natural fabrics, avoid tight clothing and dress accordingly to weather.
5) Have a change of clothes at work or in the car in case you sweat and need to change.
6) Wear clean clothes after every wash. Change clothes such as shirts or underwear several times a day, as needed.
7) Keep scented bar soaps tucked in with clothes to give them a pleasant scent. This can help mask mild bad odor.
8) Try to keep problematic areas dry. Baby powder can be applied under arms for this purpose.
9) Shave in the evening and leave skin to recover. Wash underarms thoroughly in the morning, pat dry and apply antiperspirant and deodorant.
10) Treat any existing conditions. For example, treat athlete’s foot with topical antifungals.
11) See your doctor for long-term treatment options for excessive sweating that may cause bad smell. Injections to stop sweating, interventions to nerves or removing some sweat glands are available options with long-term or permanent effects.
12) Lose weight, stop smoking and drinking coffee and alcohol for better body smell.
13) Avoid spices such as chili peppers, wasabi or horseradish, pungent foods such as garlic, onions, leek or chives, cabbage family vegetables rich in natural sulfur compounds such as broccoli, cabbage, cauliflower, broccoli rabe, Brussels sprouts and asparagus.
14) If you have fish odor syndrome, limit intake of red meat, fish, eggs, especially duck and goose eggs, milk, dairy and legumes.