Having sweaty, smelly feet stinks. Not only literally but also because it can cause various adverse effects.

The medical term for severe, chronic sweating of the feet is plantar hyperhidrosis.

• plantar – concerning the sole of the foot.
• hyperhidrosis – excessive sweating.

What is plantar hyperhidrosis?

We all sweat in order to cool down our bodies. Otherwise we would overheat. Your body has millions of sweat glands which are concentrated in your feet, hands and forehead.

Most of these sweat glands are so called eccrine glands which secrete a clear, odorless fluid that plays a role in evaporative heat loss.

When these eccrine glands are overactive they cause much sweating and we speak of hyperhidrosis.

So although this sweat, basically water and salt, does not stink it will soon when bacteria living on your feet start to feed on it.

Why does it cause your feet to stink?

Bacteria called Staphylococcus epidermidis, Brevibacterium linens, and Bacillus subtilis feed on an amino acid called leucine, found in the sweat produced by the eccrine glands in your feet.

Ironically, especially the bacteria with subtilis in their name are responsible for a truly offensive odor. Brevibacterium linens however is most often the cause of foot odor. This smell is also called plantar bromhidrosis.

When these bacteria feed on leucine, isovaleric acid is released. This is the well-known penetrating scent that makes Swiss cheese so quickly recognizable. Just as it immediately lets you know someone has smelly feet.

In some people this condition is pretty severe. By taking of his or her shoes they can clear out a room faster than a gassy skunk on a chili bean diet.

But not only the stench is a problem.

Profusely sweating of the feet can cause some other nasty side effects too.

Hyperhidrosis side effects

Plantar hyperhidrosis/ bromhidrosis interferes with your daily activities and can seriously affect your quality of life.

Excessive sweating in the feet can contribute to secondary infections and other skin problems on their feet. Hyperhidrosis often requires medical care.

Complications of plantar hyperhidrosis include:

• Macerated skin. The constantly moist feet become more vulnerable. Skin may become white, wrinkled, and cracked. Skin degradation can cause the feet to become tender or painful.

• Scaling of the feet. Peeling and scaling on the bottom of the feet and in between the toes. Recognized by scaly loose skin, red skin or white areas between your toes and under your feet.

• Itchy feet. Often caused by athlete’s foot or atopic dermatitis. The feet may become painful too.

• Skin texture abnormalities such as small craters (pitting)

• Blisters. Sore skin is more likely to form blisters.

• Fungal infections. Mycosis. If your feet sweat profusively you are likely to be prone to skin infections. These infections can range from warts (Verruca plantaris) to ringworm and fungal nails.

• Athlete’s foot. Ringworm of the foot, tinea pedis. The immoderate moisture increases the chance on development of athlete’s foot. The fungi that cause this condition require moisture and warmth to grow and thrive.

• Other skin conditions. Certain skin conditions, such as eczema and skin rashes, occur more frequently in people with (plantar) hyperhidrosis.

• Skin inflammation. Contact dermatitis. Excessive sweating may worsen skin inflammation causing the area to become red and inflamed.

• Slippery feet in sandals and other footwear may cause dangerous situations.

• Social and emotional effects. Psychosocial discomfort. Having smelly, hot, painful feet and perspiration-soaked socks can be embarrassing and cause stress. Especially when it’s required to take off or switch footwear.