Bad Armpit Odor (Smelly Armpits) Causes and Remedies

It is a common problem that affects almost every adult to some degree or the other eventually but some people have very smelly armpits that can affect their daily functioning. Offensive odors arises for a number of reasons. Most of us are able to mask it with deodorant and perfumes in conjunction with daily bathing that reduces the contributing factors to bad body odor. However, the armpit is one of those areas which are more likely to smell bad much sooner for a number of reasons.

Natural and Offensive Armpit Odors

Bad odors emanating from the body is due to a combination of factors. The reason why it is so prominent in the armpits is due to the fact that the armpits are an enclosed area, with thicker hair, warmth due to poorer ventilation and increased tendency to sweat as compared to other parts of the body. This is similar to the micro-environment created around with groin with clothing and around the feet with closed shoes. It is therefore not surprising that the armpits, groin and feet are considered to be the more smelly surface areas of the body.


The surface of the skin is teeming with millions of bacteria. Most of these bacteria are harmless to human skin unless there is lowered immunity or a break in the skin. These bacteria along with some fungal species are known as the skin flora. It feeds of dead skin cells, sweat and skin oils. As a result of its presence, these bacteria releases gases into the environment. Some of these gases can have an offensive odor and it is the main reason for bad body odors.

Sweat and Oil

Sweat is made up of water, electrolytes and waste substances. The latter is some of the same wastes that are expelled through the kidney in the form of urine. It can have an offensive ammonia-like smell similar to urine. This is further compounded by the presence of bacteria on the skin that may consume it and then release offensive smelling gases.

Skin oils (sebum) are secreted by the oil-producing glands. It moisturizes skin and hair in the area. However, there is evidence that these oils may also contain certain compounds known as pheromones which may have a distinctive odor. It is believed to play a role in social communication between genders although this has not been conclusively proven.


Armpit hair is one of the secondary sexual characteristics indicative of puberty. It is therefore present in adolescents and adults as thicker hairs in the armpits. As with hair anywhere on the body, sweat, skin oils, dead cells and bacteria can adhere to it. Hair may also reduce heat loss thereby making the armpits warmer which in turn increases sweating and allows for bacteria to thrive in optimal temperatures. Therefore hair indirectly contributes to offensive odors.

Causes of Smelly Armpits

The factors mentioned above can lead to offensive armpit odors even under normal circumstances, meaning that there is no excessive sweating, no excessive bacterial growth and even without any armpit hair. However, the following conditions are more likely to contribute to smelly armpits.

Environment, Diet and Lifestyle

All of us are well aware that we will sweat more when it is hot or when we are dressed very warmly. Some people are more temperature sensitive than others and will therefore sweat easily. Exercise also has the same effect as sweating increases during strenuous physical activity. The purpose of the increased sweat in these cases is to cool down the body.

Sometimes sweat is also secreted in larger amounts when eating certain foods. This is mainly seen with spicy foods but it is usually a momentary change in sweating. Strong emotions can also trigger sweating. This includes fear, sadness, anger, happiness and pleasure but as with other environmental, dietary and lifestyle measures the increased sweating is usually temporary.


Hyperhidrosis means excessive sweating. While we all perspire more on some days and less on others, people who suffer with hyperhidrosis experience excessive sweating even when there is no environmental factors to trigger it. This excessive sweating is due to overactivity of the sweat glands and may be linked to nerve and hormonal factors.

Other Causes

Less commonly, kidney and liver disorders can cause a change in body odor. It rarely occurs on its own and other symptoms of kidney and liver dysfunction are usually present. A sickening sweet odor may be present with diabetes but this is more prominent in the breath. People with an overactive thyroid gland tend to experience increased sweating which can also affect body odor.

Remedies for Smelly Armpits

  • Proper hygiene is the first step in dealing with smelly armpits. It is important to bathe at least twice daily and wash the armpits thoroughly. An antibacterial soap may be a better option as it reduces the bacterial population on the skin surface.
  • Use antiperspirant deodorants or drying powders on the armpits after bathing at the start of each day. It should be avoided if it causes any skin irritation in the area to prevent skin infections that can also play a role in bad armpit odor.
  • Wear lighter colored clothing that allows for easy movement of air. The color and ventilation will reduce the build up of heat under the armpits thereby easing the need for more sweat as a cooling mechanism.
  • Remove armpit hair if other measures fail. It should be done carefully so as not to injure the skin of the armpit which can then become infected with bacteria and further contribute to smelly armpits.
  • Drink plenty of water. Although not conclusively proven as a remedy for offensive body odor, the increased water consumption will allow for components such as urea which are in both sweat and urine to be flushed out faster and more effectively.
  • Reduce alcohol intake as the byproducts of alcohol are secreted through sweat. While alcohol has a characteristic odor, it may also mix with other contributors of an offensive odor to worsen the bad smell.

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