08/06/2016 10:50 AM AEST | Updated 15/07/2016 12:53 PM AEST

Why Your Shoes Are Smelly (And What Can Be Done About Them)

It’s not just the material they're made from, it’s actually your feet.

Leave your stinky shoes at the door. Outside.

Hey, stinky, ever wondered why your feet or shoes smell? And why this tends to be more apparent in winter?

"If somebody finds their shoes are smelly it is most often due to the odour of the person's feet that over time has absorbed into the shoes," Podiatrist Vanessa Griffiths told The Huffington Post Australia.

"There are actually more sweat glands in our feet than anywhere else in the body. Feet start to smell when bacteria on the skin break down sweat as it comes from the pores. A awful 'cheesy' smell is released as the sweat decomposes. It is this smell that then permeates our shoes."

Shoes should be rotated throughout the week, not worn two days in a row.

So it turns out it's sweat's fault, not your boots or ballet flats. The scent is arguably more noticeable in winter because you're likely to be wearing fewer sandals and more closed-in shoes, and homes tend to be closed up more due to the cold. While your feet sweat in all closed in shoes, synthetic fibres can make you sweat more.

"Synthetic shoes and man made fibres should definitely be avoided when selecting shoes as leather and any other natural fabrics will not cause the feet to sweat as much," Griffiths said.

If you feel your feet are a bit on the nose, avoid wearing the same pair of shoes everyday.

"The cause of the person's sweaty feet could be due to them wearing the same shoes everyday, so the sweaty feet smell gets absorbed into the fabric of the shoe. Shoes should be rotated throughout the week, not worn two days in a row. Air them out at night, undo any laces and open them up wide. Make sure you wash regularly and avoid nylon stockings and any synthetic fibres," Griffiths said.

Hormones may be to blame, too.

"Hormonal changes as a teenager or in pregnancy can cause an increase in sweat, too. Hyperhidrosis, which is a condition where you sweat more than usual, is responsible for smelly feet and of course poor personal hygiene."

Dirty old shoes belong in shoe heaven.

If you have a favourite pair you want to rescue (or wish to avoid odour before it happens), try tea tree oil.

"Tea tree oil is a wonderful product to reduce smelly shoes. Washing shoes in the washing machine often does not rid them of the smell, so tea tree oil is the secret weapon. Often sweaty feet cannot be avoided, thus shoes inevitably end up smelling. A sprinkle of a few drops of tea tree oil through the shoe will reduce any odour and is also a great prevention of odour," Griffiths said.

"If you are tempted to apply tea tree oil directly to skin please make sure it is heavily diluted or in spray form as in its undiluted form it can be quite potent and even cause burns on the skin."