Body odour, also known as bromhidrosis, is the unpleasant smell that can occur when you sweat.

The sweat itself doesn't smell. The unpleasant odour is produced by bacteria on the skin that break down the sweat into acids.

Sweat glands

There are 3-4 million sweat glands on the human body. The two types of sweat gland are:

• eccrine glands – which are spread across the skin and regulate body temperature by cooling the skin with sweat when you get hot
• apocrine glands – which are mainly found in hairy areas of the body, such as the armpits and genital area; apocrine glands develop during puberty and release scented chemicals called pheromones

Sweat produced by the eccrine glands is usually odourless, although it can smell if bacteria start to break it down.

It can also take on an offensive odour if you consume certain food and drink, such as garlic, spices and alcohol, as well as some types of medication, such as antidepressants.

However, it's the apocrine glands that are mainly responsible for body odour, because the sweat they produce contains high levels of protein, which bacteria find easy to break down.

People who sweat excessively from their apocrine glands, or have a lot of bacteria on their skin, tend to have worse body odour.

Who gets body odour?

Anyone who has reached puberty (when the apocrine sweat glands develop) can produce body odour. Men are more likely to have body odour, because they tend to sweat more than women.

Things that can make body odour worse include:

• being overweight
• eating rich or spicy foods
• certain medical conditions, such as diabetes

Managing body odour

The best way to avoid getting body odour is to keep areas of your body that are prone to sweating clean and free of bacteria.

Use soap to wash every day, paying particular attention to the areas that produce the most sweat, such as your armpits, genital area and feet. Washing removes sweat and reduces the number of bacteria on your skin. Changing and washing your clothes regularly will also help.

Using an antiperspirant or deodorant daily will help prevent body odour. Antiperspirants work by reducing the amount of sweat your body produces. Deodorants use perfume to mask the smell of sweat.

Regularly shaving your armpits can also help reduce body odour. The hair in your armpits traps sweat and odour, providing ideal conditions for bacteria to multiply.

In very severe cases of body odour, surgery or treatment with botulinum toxin may be possible options.

Read more about how to treat body odour.