Foot Odor and Sweaty Feet

Why Do Feet Smell?

Foot odor, whether it’s mild or the room clearing kind, is due to a combination of sweat and footgear (the socks and shoes we wear).  With more than 250,000 sweat glands each, feet are among the most perspiring parts of the body.  In one day, each foot can produce more than one pint of sweat!   

Sweat is basically composed of just salt and water, so it does not have a smell of its own.  The smell occurs when bacteria that normally live on the skin eats the sweat and excretes waste that has a strong odor. The bacteria combined with sweat produce Isovaleric acid which actually causes the odor.

So why don’t our hands, which have about the same number of sweat glands per square inch as our feet have, produce foul odors?  Because hands are exposed to the air and the sweat has a chance to escape into the air, or evaporate.  Sweat does not accumulate on our hands as it does on our feet.

Feet on the other hand, are trapped inside socks and shoes, where temperatures can easily reach 100 degrees Fahrenheit.  The perspiration, which cannot escape into the air (evaporate) due to lack of airflow in the shoe, combines with the dark warmth of the shoe to create a breeding ground for bacteria. When the increased numbers of bacteria feed on the sweat, more foul smelling bacterial wastes are produced.  The more waste produced, the worse the foot odor.


How Sweat Works

Healthy People Sweat…there’s no stopping it…and it’s normal!

Our body produces sweat because it is a very efficient way to cool ourselves down when we become overheated.  When sweat evaporates from the surface of the skin, it removes excess heat and cools us down

Factors that cause normal sweating include:

  1. Exercise or other strenuous activities.
  2. Hot weather.
  3. Weight and material of the clothing and shoes we wear.
  4. Nervousness, anxiety, or stress

Some people sweat more than others. Some causes of excessive sweat production are:

  1. Heredity: Some people inherit a tendency to sweat excessively, especially on their palms and the soles of their feet.
  2. Certain foods and beverages: Drinking hot beverages and those that contain caffeine and alcohol can make you sweat. Eating spicy foods can do the same.
  3. Certain medications: Drugs that may increase sweat production include:
    excess doses of the thyroid hormone thyroxin, some medications used to treat mental disorders, and morphine
  4. Low blood sugar (hypoglycemia): One of the signs and symptoms of low blood sugar is excessive sweating. Once the normal level of sugar is restored to the blood, perspiration production returns to normal.
  5. Fevers: When our temperature rises, the body tries to reduce the increased temperature, or cool itself down, by increasing sweat production.
  6. Overactive thyroid (Hyperthyroidism): One of the symptoms of over-production of the hormone thyroxin by the thyroid gland is increased sweating.
  7. Menopause: A drop in estrogen levels in women going through menopause may experience hot flashes – a rise in temperature accompanied by sweating.
  8. Low levels of male hormones: Decreased production of testosterone may produce hot flashes in men, causing a rise in body temperature and increased sweat production.

Treatments & Prevention

Because foot odor is due to the interaction between our perspiration and the bacteria that inhabit our skin, socks, and shoes, any attempt to reduce the odor has to address both our sweating and footgear.

Fortunately, foot odor can be controlled with a few preventive measures that include:

  1. Practice good foot hygiene to keep bacteria levels at a minimum:
    1. Bathe your feet daily with a foot wash designed to kill those germs that occur most frequently on the feet. Many foot and ankle specialists recommend the daily use of Dr. Smith’s Deodorizing Foot Wash for this purpose.
    2. Change your socks daily and shoes at least once every other day.
    3. Before putting on socks, apply PediFix Podiatrists’ Choice Soothing Foot Powder, which helps keep feet dry and cool throughout the day.
    4. Dead, dry, callused skin acts like a sponge, absorbing perspiration and staying soggy for hours. This soggy dead skin becomes an ideal environment for odor producing bacteria. Removing the dead skin and calluses will go a long way in eliminating foot odor. Doctors recommend the Foot Buffer Pro.
  2. Socks and shoes need special care to prevent them from contributing to foot odor:
    1. Wear socks that are made with 60-70% cotton and 30-40% man made fibers such as Lycra. The Lycra fibers whisk perspiration away from the feet, while the cotton fibers absorb the perspiration. This removes the sweat from your feet, stopping skin bacteria from eating it and producing foul smelling wastes (foot odor).
    2. Wash socks in hot water, but not in bleach, which may irritate the skin.
    3. Wear shoes that are made of porous materials such as leather and canvas. Materials that allow a free flow of air in and out of the shoe. Leather is recommended.
    4. Some shoes, including leather shoes are made with plastic liners. Plastic liners inhibit airflow, so avoid shoes with these liners.
    5. Regular use of the SteriShoe® Ultraviolet Shoe Sanitizer kills up to 99.9% of the germs that cause foot infections and offensive shoe odor. Doctor tested and recommended. SteriShoe is a safe, easy and highly effective way to provide a healthier in-shoe environment for feet!
    6. For persistent or severe sweat and odor problems, aluminum chloride hexahydrate 20% solution can be used.

Complications Caused by Sweaty Feet Include:

  1. Athlete’s Foot is caused by a fungal infection of the skin of the feet. People who sweat profusely are prone to these types of infections, because fungi thrive in warm, moist, dark environments such as sweaty shoes. For more information about Athlete’s Feet, including symptoms and treatment, click here.
  2. Fungal Nail Infections also occur more frequently in people that sweat excessively.

A Final Word: Many people are so embarrassed by their foot odor that they won’t discuss it with their doctor. To this I say: doctors treat and see some pretty gross problems during an average day, and that foot odor is nothing in comparison to some of these problems. Do not hesitate to ask your doctor about this condition.