<Things you should know> The correct knowledge about "odor": Causes, prevention, and treatment of "body odor" (specifically underarm odor). Basic knowledge about body odor (specifically underarm odor) Main causes and mechanisms of body odor (specifically underarm odor) Main causes of body odor (axillary osmidrosis) Is this body odor? A self-check method you can do right now Actually, it's surprisingly common!? Female body odor Common methods for preventing body odor Common ways to deal with body odor (specifically underarm odor) Being mindful of one's own body odor is considered a matter of etiquette when interacting with others. In today's world, where this is a common understanding, body odor, specifically underarm odor (bromhidrosis), is a very troublesome condition. What is the mechanism by which body odor occurs? What are the main causes and treatments? We will provide a detailed explanation of body odor, supervised by a dermatologist. Basic knowledge about body odor (specifically underarm odor) Body odor, specifically underarm odor (bromhidrosis), is not uncommon, so most people have probably heard of it. However, many people mistakenly believe that "strong body odor" equals underarm odor. Therefore, we've started by summarizing some basic information about underarm odor. What is body odor (specifically underarm odor)? The term "wakiga" (body odor) originates from the fact that the odor originates in the armpits (waki) and under the arms (ga). Medically, it is called "axillary osmidrosis" or "apocrine bromhidrosis."Furthermore, leaving underarm odor untreated will not harm your health or worsen it. Our bodies have sweat glands, which are tissues that secrete sweat. There are two types of sweat glands: eccrine glands and apocrine glands. The sweat secreted by apocrine glands is the main cause of body odor (specifically underarm odor). (More details below). It doesn't happen to everyone; it occurs in people with a large number of apocrine glands. About the smell Body odor, particularly underarm odor, has a distinctive smell that is often described as a "pungent, spicy smell" or a "sulfurous smell." Furthermore, the medical text "Zhubing Yuanhou Lun," written during the Sui Dynasty in China, refers to it as "fox odor," suggesting it was perceived as resembling the smell of foxes or badgers. Main causes and mechanisms of body odor (specifically underarm odor) Body odor (specifically underarm odor) is caused by sweat secreted from the apocrine sweat glands. This sweat contains organic acids such as proteins and lipids, which are broken down by the bacteria naturally present in the armpits, resulting in that distinctive, unpleasant smell.While eccrine sweat glands are found throughout the epidermis of the entire body, apocrine sweat glands are found only in hair follicles in specific areas such as the armpits, nipples, and genitals. In other words, the number of apocrine sweat glands is related to the amount of hair, and people with severe body odor (bromhidrosis) almost always have a large amount of armpit hair. Main causes of body odor (axillary osmidrosis) Body odor, or underarm odor, affects approximately 1 in 10 Japanese people. But what are the differences between those who develop body odor and those who don't? Let's take a look at the main causes of body odor. Genetics If both parents have body odor (specifically underarm odor), their child is much more likely to develop it as well. The probability of heredity is even higher when both parents have the condition compared to when only one parent does. The effects of sex hormones Sex hormones have the effect of activating the apocrine sweat glands. This is why symptoms of body odor (specifically underarm odor) are not seen until puberty. Although babies have apocrine sweat glands, they become more active when sex hormones are secreted.In women, symptoms of body odor may temporarily appear during periods strongly influenced by sex hormones, such as pregnancy, childbirth, and menstruation. Disruption of lifestyle A poor diet, such as rarely consuming vegetables or fish, excessive drinking or smoking, or suffering from stress can all contribute to the development of body odor (specifically underarm odor). Is this body odor?Self-check methods you can do right now There are no clear criteria for diagnosing body odor (axillary osmidrosis). It's difficult to determine if you have body odor based on such an ambiguous factor as smell alone. Here, we'll introduce a simple self-check method. The earwax is wet and there is a lot of ear hair. There are no eccrine sweat glands in the external auditory canal. Therefore, it is highly likely that the moisture in earwax is due to sweat secreted from apocrine sweat glands. If there are apocrine sweat glands in the external auditory canal, there are almost always many apocrine sweat glands in the armpits as well.Furthermore, since apocrine sweat glands are located inside hair follicles, if earwax is moist and there is a lot of hair in the ear canal, it is safe to assume that apocrine sweat glands are present, meaning that the person has body odor (specifically, underarm odor). Underwear, T-shirts, and other clothing that touches the armpits will become stained. The underarm sweat of people without body odor is clear. This is because the sweat secreted from eccrine sweat glands is mostly water with a small amount of salt. On the other hand, people with body odor have many apocrine sweat glands in their armpits, and a large amount of apocrine sweat is secreted. Apocrine sweat contains various substances such as proteins, lipids, carbohydrates, iron, and ammonia, which leaves a yellowish stain on clothing that comes into contact with the armpits. I often eat high-calorie and high-fat foods such as meat. Consuming excessive amounts of high-calorie and high-fat foods, such as meat, can lead to subcutaneous fat accumulation. This fat then stimulates the activity of apocrine sweat glands and sebaceous glands, ultimately causing body odor (bromhidrosis). It is believed that this dietary lifestyle plays a significant role in why body odor is more common among Westerners than among Japanese people. I've had family members and others around me point out that I have underarm odor. Whether or not people around you point out the smell of your armpits is a very important point in determining whether or not you have bromhidrosis (body odor). Odor is a delicate issue and difficult to talk about with others, so it's a good idea to ask close family members or friends. In fact, there are many cases where people go to the hospital thinking they have bromhidrosis, but are actually suffering from olfactory reference syndrome (a phobia of body odor) where they are overly sensitive to their own smell. In addition, having a family history of body odor (bromhidrosis) or having thick body hair can also increase the likelihood of having it yourself. If you check the above points and are concerned about underarm odor, it might be a good idea to consult a dermatologist. Actually, it's surprisingly common!? Female body odor In women, underarm odor can temporarily intensify during menstruation, pregnancy, and childbirth. These bodily changes unique to women are caused by the action of female hormones, and the apocrine sweat glands are also affected by them.Furthermore, in many cases, underarm odor becomes less noticeable after menopause, when the secretion of female hormones decreases. [Reference] Underarm odor is surprisingly common in women! Its mechanism and care methods Common methods for preventing body odor Since body odor (specifically underarm odor) can have a genetic component, prevention alone may not completely eliminate the smell in all cases. However, the following methods can help reduce the level of odor. Improving your diet High-calorie, high-fat foods, including meat, may contribute to body odor. Foods rich in dairy fat, such as milk and butter, also fall into this category.If possible, try to focus on a diet that includes soy products and fish, even though they are still sources of protein. Refrain from drinking alcohol and smoking. Alcohol and nicotine stimulate the sweat glands. Ingesting them activates the apocrine sweat glands, so it's best to limit your intake. Furthermore, alcohol and nicotine themselves are strong odor-causing components, so even if you don't have a predisposition to body odor, they can cause body odor to become stronger. Don't let stress build up. When you're stressed, your sympathetic nervous system becomes dominant. This can cause you to sweat (such as cold sweats) even when it's not hot. This is called psychogenic sweating. Since sweat is the cause of body odor, psychogenic sweating is a major enemy when it comes to controlling the smell. Try to avoid accumulating stress. Develop an exercise habit Frequent exercise and sweating can promote the elimination of waste products. Since waste products are involved in bacterial growth, reducing their amount can reduce body odor. In addition, moderate exercise can also help relieve stress.However, when you exercise and sweat, underarm odor can sometimes become temporarily stronger. Be sure to wash the affected area thoroughly. Common ways to deal with body odor (specifically underarm odor) Body odor, or underarm odor, can vary greatly in severity. For mild cases, simply following the methods below can significantly reduce the odor. Wipe away underarm sweat frequently. By frequently wiping away sweat, which is the cause of body odor, you can reduce underarm odor. Removing underarm hair Hair in the armpits promotes bacterial growth. If odor is a concern, it's recommended to remove the hair. Use antiperspirants or antibacterial agents. Applying antiperspirants to the underarms to suppress sweat secretion, or antibacterial agents to inhibit bacterial growth, is also effective. These are available in various forms such as ointments, sprays, lotions, and powders. If the odor persists after trying the above, you should consult a dermatologist or plastic surgeon.Treatment methods vary depending on the cause and severity, but include surgery to remove apocrine sweat glands and sebaceous glands, destroying them with electricity, and suppressing sweating with Botox injections. If you are diagnosed with body odor by a doctor, some treatments may be covered by insurance, so it is recommended that you consult with a doctor first. Supervised by: Dr. Hiroyuki Sato, Director of Jimbocho Station Front Dermatology ClinicAfter graduating from the University of Tokyo Faculty of Medicine, he worked at several hospitals, including the university's affiliated hospital, the Cancer Institute Hospital of Japan, and the Japanese Red Cross Medical Center, before opening Jimbocho Ekimae Dermatology Clinic in 2014. He is a certified dermatologist by the Japanese Dermatological Association. We take care to post accurate information,Please point out any incorrect information. Please submit any comments regarding medical information here. Return to the list of guides categorized by health symptoms.