What is hyperhidrosis?
Hyperhidrosis, or excessive sweating, is a relatively rare, non-life-threatening medical condition that occurs in the:
- Hands (palmar hyperhidrosis);
- Armpits (axillary hyperhidrosis); or
- Feet (plantar hyperhidrosis)
Regardless of where it occurs, hyperhidrosis affects a person’s quality of life.
What causes hyperhidrosis?
No clear cause of hyperhidrosis has been identified to date. To better understand why hyperhidrosis occurs, it is important to recognize that sweat is required by the body as a coolant to protect against overheating. Your body has several million sweat glands distributed over it, the bulk of which are eccrine glands that secrete odorless, clear fluid that helps regulate body temperature through evaporative heat loss. Generally, hyperhidrosis involves overactive eccrine glands.
The apocrine glands are the other type of sweat glands, which are found in the armpits and genital area. Apocrine glands produce a thick fluid that produces body odor when it comes in contact with bacteria on the skin’s surface.
Nerves activate both the eccrine and apocrine glands. These nerves (from the autonomic nervous system) become active due to a variety of stimuli, including:
- Physical activity or exercise
In patients with hyperhidrosis, sweat glands (eccrine glands in particular) overreact to stimuli, producing more sweat than is needed.
Overall, there are two types of hyperhidrosis, both of which may be inherited:
- Generalized hyperhidrosis
- Localized hyperhidrosis
Generalized hyperhidrosis: Affects large areas of the body with excessive sweating, typically in adults whose sweating occurs during both waking and sleeping hours. Generalized hyperhidrosis may be caused by:
- Heat, humidity, exercise
- Infections, such as tuberculosis
- Malignancies (Hodgkin disease, cancer of the lymphatic system)
- Metabolic diseases and disorders, including hyperthyroidism, diabetes, hypoglycemia, pheochromocytoma (a benign tumor of the sympathetic nervous system), gout, and pituitary disease
- Severe psychological stress
- Some prescription drugs
- Autonomic dysfunction
Localized hyperhidrosis: Specifically affects the palms, soles, armpits and face. Unlike generalized hyperhidrosis, it usually begins in adolescence, but can also manifest in childhood or even in infancy. Localized hyperhidrosis typically does not occur during sleep and is commonly caused by:
- Emotional stress, especially anxiety
- Certain odors
- Certain foods, including citric acid, coffee, chocolate, peanut butter and spices
- Spinal cord injury
Who is affected by hyperhidrosis?
People of all ages and genders can be affected by hyperhidrosis. This condition affects millions of people around the world (approximately 3 percent of the population), but because of lack of awareness and understanding that there are treatments for the condition, more than half of these people are never diagnosed or treated for their symptoms.
Is hyperhidrosis serious?
Hyperhidrosis is not a serious or life-threatening condition, although it often interferes with normal, daily activities and affects a person’s quality of life. Severe, chronic sweating may make the affected skin white, wrinkled, and cracked, often causing the area to become red and inflamed. Hyperhidrosis often requires medical care.
How is hyperhidrosis diagnosed?
When hyperhidrosis is suspected, your doctor will perform a thorough physical exam. Several tests may be performed, including:
- Starch-iodine test: An iodine solution is applied to the sweaty area and starch is sprinkled over the iodine solution. The starch-iodine combination will turn a dark blue color indicating where there is excess sweat production.
- Paper test: Special paper is placed on the affected area to absorb sweat, and then weighed to determine the amount of sweating that occurs.
- Laboratory tests, such as thyroid function tests, blood glucose and uric acid level measurements, and urine samples are performed to rule out more serious medical conditions that may be associated with excessive sweating.
How is hyperhidrosis treated?
There are a variety of treatment options for patients with localized hyperhidrosis. Typically, your physician will initially treat hyperhidrosis with ointments or salves that "dry up" sweat glands.
Antiperspirants, both prescription (such as Drysol) and non-prescription also decrease sweating in not only the armpits, but also can be used to treat mild cases of hyperhidrosis of the hands and feet.
Medical treatment: One medical treatment option for hyperhidrosis is iontophoresis, which requires the hands or feet to be placed into a shallow pan of water that an electrical current is passed through. A medical device sends a low-voltage current through the water, "stunning" the sweat glands and decreasing the secretion of sweat for period of six hours to one week. Iontophoresis is most effective if it is completed every other day for about six to ten treatments. After completing a series of treatments, up to 80 percent of patients may stop sweating. However, this treatment can be painful.
The injection of Botulinum Toxin A (Botox) into the affected areas is another treatment option. This toxin affects the nerve endings and decreases the transmission of the nerve impulses to the sweat glands, decreasing sweating. Several injections of Botox are required for the best possible results, and can relieve symptoms for as long as 12 months.
Surgery: When medical treatments have failed to offer adequate control of hyperhidrosis, your physician may recommend surgery. Surgery may be recommended for severe cases of palmar or axillary hyperhidrosis that have not responded to medical therapy. Your physician will determine if surgery is the appropriate treatment for you.
If surgery is needed, a minimally invasive procedure called video-assisted thoracic sympathectomy (or thoracoscopic sympathectomy) may be used. This involves interrupting a specific portion of the main sympathetic nerve, which is a part of the autonomic nervous system. The sympathetic nerve "chain" is made up of a network of nerves that branch off from the spine and form next to the ribs in the chest.
Each sympathetic nerve branch originates from a bundle of cells called a "ganglion." Through two small incisions under the armpit, a specific ganglion that causes sweating is located and removed. Then the signal which tells the body to sweat in a specific region is ‘turned off’, reducing localized hyperhidrosis. The exact ganglion that is removed depends on the area of excessive sweating that is being treated.
The patient is under general anesthesia during the video-assisted thoracic sympathectomy procedure. By inserting a small camera, called a thoracoscope, the surgeon is guided to the appropriate ganglion. Once the nerve is detected, it is interrupted. After completing the procedure on one side of the body, the surgeon then performs the same procedure on the opposite side. This procedure is usually completed within two hours, and most patients go home the day of surgery.
What are the benefits of minimally invasive surgery to treat hyperhidrosis?
Minimally invasive approaches, such as thoracoscopic sympathectomy, offer many benefits including:
- Limited number of small incisions
- Shorter hospital stay
- Reduced pain
- Rapid recovery time
- Quicker return to daily activities
What are the risks of minimally invasive surgery?
Thoracoscopic sympathectomy is an effective treatment for hyperhidrosis, especially when treating excessive sweating of the palms, but like any type of surgery, the procedure is not without risks or potential side effects. The primary side effect is compensatory hyperhidrosis, or sweating in other areas of the body that were once free of sweating. Compensatory hyperhidrosis occurs in approximately 70 percent of all patients treated by thoracoscopic sympathectomy, but is usually well-tolerated.
After surgery for palmar hyperhidrosis, many patients notice that their hands are warm and dry as opposed to "cold and clammy."
Another potential side effect is gustatory sweating, or increased sweating when eating. This side effect occurs in approximately 5 to 10 percent of patients who are treated with thoracoscopic sympathectomy.
Rarely, the patient may develop Horner’s syndrome, which results when the highest sympathetic ganglion on the nerve is damaged during the operation. Occurring very rarely, Horner’s syndrome causes a slight droop in the eyelid, a small or narrow pupil, and the lack of sweating on the side of the face where the ganglion is damaged. The syndrome may resolve over a period of time on its own.
Additional possible complications of thoracoscopic sympathectomy include:
- Artery, nerve, or vein damage
- Cardiac problems, such as abnormal rhythm
- Blood clots
- Urinary tract infection
Overall, thoracoscopic sympathectomy will relieve symptoms in approximately 95 to 98 percent of patients with excessive hand (palmar) hyperhidrosis and approximately 75 to 80 percent of patients with armpit (axillary) hyperhidrosis. Thoracoscopic sympathectomy for hyperhidrosis of the feet (plantar) is not as effective, with only 25 percent of patients showing improvement.
Thoracic Sympathectomy for Severe Hyperhidrosis: Impact of Restrictive Denervation on Compensatory Sweating. Annals of Thoracic Surgery 2006. 81:1048-55.