Man doing sit ups on the floor

Why does my sweat smell?

Unlike most types of sweat, cold sweats aren’t caused either by heat or working your body hard. They’re actually caused by our body’s ‘fight or flight’ response, which is designed to protect us in dangerous situations.

When we feel nervous, anxious or threatened, our breathing and heart rate naturally speed up, sending our body into ‘overdrive’. That, in turn, switches on our sweat glands to keep us cool.

A cold sweat could be brought on simply by watching a scary movie. But if you’re experiencing regular cold sweats, there are certain health conditions your body may be trying to make you aware of. So, you might want to talk to your doctor.

A boy looking stressed out with the words only you can move you written across the image

Why sweat makes scents

The scent of sweat is in the science. Put simply, your apocrine glands produce an odorless secretion which is broken down by bacteria on the surface of the skin. Bacteria use the apocrine secretion as a source of food – it’s the by-products of this process which smell [1]. Apocrine sweat has more nutrients than eccrine sweat which is what your body produces during exercise – mainly just salt and water). Stress and anxiety trigger more apocrine sweating which is why there is more body odor.

Does anxious stress sweat smell different to exercise sweat?

It does! Whether you’re working out in the gym or working out how to squeeze another meeting into your full calendar, we get sweaty and smell different. Why? There are two types of sweat glands in the body: apocrine and eccrine. When you get stressed, the apocrine glands – mainly in the armpits – produce sweat. Stressful situations also cause your heart rate to increase, encouraging hormones and adrenaline to flood the body which brings additional sweat from your eccrine glands.

Can diet affect how sweat smells?

Sweat can definitely be affected by the foods we consume. For example, when you eat lots of garlic or a strong curry, your sweat can smell of it for several days afterwards [2]. Following a ketogenic diet can produce keto body odor which kind of smells like nail polish remover – or your sweat smells like ammonia.

Why do underarms smell so bad?

The underarm is warm and damp and the unique mix of ingredients in your sweat make the perfect environment for bacteria to grow and generate body odor [2.5]. There are tens of millions of bacteria on each square centimeter of underarm skin – but this is nothing to be alarmed about as the majority of them are completely harmless [3].

How to get rid of underarm odor

When it comes to avoiding underarm odor, prevention usually works better than cure.

Start feeling fresh:

  • Have a bath or shower (at least) once a day and wash your clothes regularly
  • Avoid strong-smelling foods (garlic, curry etc.)
  • Wear an anti-perspirant at bedtime. Sure has a Nonstop protection anti-perspirant deodorantOpens in a new window that protects against sweat and odor for 72 hours. Wearing it overnight prevents sweating, so you wake up feeling and smelling fresher
  • Try to keep your underarms dry as possible

1 (Source: Leyden, J.J., McGinley, K.J., Holzle, E., Labows, J.N., Kligman, A.M. (1981) The microbiology of the human axilla and its relationship to axillary odor. J. Invest. Dermatol., 77, 413-416)

2 (Source: Wigley, L. (2000) The apocrine gland - A review of current knowledge, P00 0256. Hollinger, M., Sheikholislam, B. (1991) Effects of dietary alteration on trimethylaminuria as measured by mass spectrometry. J. Int. Med. Res., 19, 63-66. Senol, M., Fireman, P. (1999) Body odour in dermatologic diagnosis. Cutis, 63, 107-111)

2.5 (Source: Leyden, J.J., McGinley, K.J., Holzle, E., Labows, J.N., Kligman, A.M. (1981) The microbiology of the human axilla and its relationship to axillary odor. J. Invest. Dermatol., 77, 413-416. Lindsay, S.L., Holmes, S., Corbett, A.D., Harker, M., Bovell, D.L. (2008) Innervation andreceptor profiles of thehuman apocrine (epitrichial) sweatgland: routesforintervention inbromhidrosis. Br.J.Dermatol. 159, 653-660)

3 (Source: Leyden, J.J., McGinley, K.J., Holzle, E., Labows, J.N., Kligman, A.M. (1981) The microbiology of the human axilla and its relationship to axillary odor. J. Invest. Dermatol., 77, 413-416)

4 Source: Taylor, D., Daulby, A., Grimshaw, S., James, G., Mercer, J., Vaziri, S. (2003) Characterization of the microflora of the human axilla. Int. J. Cosmet. Sci., 25, 137-145)

72H SWEAT AND ODOUR PROTECTION