Contrary to popular belief, sweat doesn’t smell. It’s a clear, odourless liquid mostly made up of water, salt, proteins and oils. The smell that we call ‘body odour’ is actually caused by bacteria.
Our body is home to millions of harmless bacteria that help the skin’s natural defences. They survive and grow in moist, humid and nutrient-rich environments like our armpits. Bacteria feed on our sweat and metabolise it, producing by-products that have a very distinctive smell – like vinegar, cheese or onion.
What causes body odour?
The causes of body odour vary from person to person. But for the most part, smelly sweat is all down to your sweat glands and the bacteria that live on your skin.
The human body has two types of sweat glands: eccrine and apocrine. Eccrine glands are found on most areas of the body. Mostly made up of water, eccrine sweat cools the skin when your body gets too hot.
Apocrine sweat glands are found in the underarm and other parts of the body, such as the groin and around the eyes. When the sweat from these glands comes in contact with bacteria on the skin, it creates body odour. This is a totally natural process that starts during puberty.
Body odour can also be caused by:
A change in diet
A change in weather that creates more favourable conditions for the growth of bacteria
Poor personal hygiene that contributes to bacterial overgrowth
Taking certain medications
Why does my sweat smell like vinegar?
The most common cause of a vinegary odour is the process of propionibacteria. This happens when bacteria from the sebaceous glands of the body break sweat down into propionic acid.
Propionic acid comes from the same acid family as common vinegar. So, excessive sweating can lead to vinegary body odour.
How do I stop body odour?
Smelly armpits and bad body odour aren’t harmful to your health, but they can cause embarrassment. Making a few changes to your daily routine can have you feeling and smelling fresh.