Hyperhidrosis (HH) is a condition characterized by increased perspiration beyond what is necessary for normal temperature regulation in the body. Although the exact cause of hyperhidrosis is still under investigation, the mechanism is fairly clear. The sympathetic nervous system sends signals to the sweat glands, telling them to produce and release sweat. Sweating is important in controlling the temperature of the body, but in hyperhidrosis, the sweat glands are producing and releasing more than needed for temperature regulation. We don't know if it's an overactive sympathetic nervous system, a defect in the nervous system, or the response of the sweat glands to the nervous system. Regardless, the result is the same. To better understand the sympathetic nervous system, think of it as the fight or flight nervous system. Although the sympathetic nervous system is always active, it is best known for the fight or flight response. If you were to see a wild animal and take off in a full sprint, your sympathetic nervous system would jump into action, increasing heart rate, dilating pupils, widening the bronchial passages and sending blood to your muscles. This involuntary action prepares your body for action. Stress or fear (also considered part of the fight or flight response), stimulates the sympathetic nervous system, and will make you sweat or give you goose bumps.
Approximately 1% to 3% of the US population has hyperhidrosis and many body parts can be affected. The body parts most commonly affected are the palms (palmar HH), the soles (plantar HH) and the armpits (axillary HH). Although it is common for those with excess foot sweating to also have excess hand sweating, the discussion here will focus on plantar hyperhidrosis. Certain types of footwear can increase sweating in the feet, but those with hyperhidrosis can experience increases in perspiration due to anxiety or drinks with caffeine or the nicotine in cigarettes and even with spicy food. These food items don't cause hyperhidrosis, they just exacerbate it. Excessive sweating in the feet can contribute to the development of athlete’s foot, warts, blisters, infections and foot odor.
The picture to the right shows the appearance of the skin when there is too much moisture. This picture was taken after a 3 hour football game. The white and wrinkled appearance of the forefoot is a common result of both excess pressure and excess moisture. A similar appearance can occur in a condition called pitted keratolysis. Pitted keratolysis is a bacterial infection which commonly occurs in those who have hyperhidrosis. It is characterized by small pits in the skin under the ball of the foot or the heel. All of the treatments listed below are excellent for preventing and treating pitted keratolysis, but topical antibiotics may also be needed.
When there is excessive moisture around the feet, the skin on the bottom of the feet will appear wet, white, wrinkled and pitted (as seen above). Individuals who wear enclosed shoes and cotton socks or work in wet environments may experience excessive foot sweating or moisture without having hyperhidrosis. Openings in the skin may form and the feet can become tender or painful. The excessive moisture in the feet increases the chances for the development of athlete’s foot. For those with hyperhidrosis, sandals may be difficult to wear without socks because the foot slides within the sandal, making walking and driving dangerous.
Bromhidrosis is the combination of sweaty feet and foot odor. A moist, warm environment is a perfect place for bacterial growth, which is what causes foot odor. Those with hyperhidrosis have a greater chance of having foot odor because the increased moisture increases the chances for bacterial growth.
Make an appointment with a podiatrist or dermatologist in severe cases. Prescription medications or other treatments may be needed.
More information on athlete's foot.
More information on wicking socks.
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last updated 6/23/10
Disclaimer: The advice on this website is not intended to substitute for a visit to your health care provider. We will not be held liable for any diagnosis made or treatment recommended. Consult your doctor if you feel you have a medical problem.