Hyperhidrosis is the condition characterized by abnormally
increased sweating/perspiration, in excess of that required for
regulation of body temperature. It is associated with a significant
quality of life burden from a psychological, emotional, and social
perspective. As such, it has been referred to as the 'silent
Hyperhidrosis can either be generalized or localized to specific
parts of the body. Hands, feet, armpits, and the groin area are
among the most active regions of perspiration due to the relatively
high concentration of sweat glands. When excessive sweating is
localized (e.g. palms, soles, face, underarms, scalp) it is referred
to as primary or focal hyperhidrosis. Generalized or secondary
hyperhidrosis usually involves the body as a whole and is the result
of an underlying condition.
Hyperhidrosis can also be classified depending by onset, either
congenital or acquired. Focal hyperhidrosis is found to start during
adolescence or even before and seems to be inherited as an autosomal
dominant genetic trait. Primary or focal hyperhidrosis must be
distinguished from secondary hyperhidrosis, which can start at any
point in life. The latter form may be due to a disorder of the
thyroid or pituitary glands, diabetes mellitus, tumors, gout,
menopause, certain drugs, or mercury poisoning.
Hyperhidrosis may also be divided into palmoplantar (symptomatic
sweating of primarily the hands or feet), gustatory, generalized and
Alternatively, hyperhidrosis may be classified according to the
amount of skin affected and its possible causes. In this
approach, excessive sweating in an area greater than 100 cm2 (16 sq
in) (up to generalized sweating of the entire body) is
differentiated from sweating that affects only a small
Further information: Diaphoresis
The cause of primary hyperhidrosis is unknown, although some
surgeons[who?] claim it is caused by sympathetic over-activity.
Nervousness or excitement can exacerbate the situation for many
sufferers. Other factors can play a role; certain foods and drinks,
nicotine, caffeine, and smells can trigger a response.
A common complaint of patients is they get nervous because they
sweat, then sweat more because they are nervous.
Hyperhidrosis of a relatively large area (generalized; over 100 cm2)
In people with a past history of spinal cord injuries
Associated with peripheral neuropathies
Familial dysautonomia (Riley-Day syndrome)
Congenital autonomic dysfunction with universal pain loss
Exposure to cold, notably associated with cold-induced sweating
Associated with probable brain lesions
Episodic with hypothermia (Hines and Bannick syndrome)
Episodic without hypothermia
Associated with intrathoracic neoplasms or lesions
Associated with systemic medical problems
Congestive heart failure
Due to drugs or poisoning
Associated with toxins
Infantile acrodynia induced by chronic low-dose mercury exposure,
leading to elevated catecholamine accumulation and resulting in a
clinical picture resembling pheochromocytoma.
Hyperhidrosis of relatively small area (less than 100 cm2)
Idiopathic unilateral circumscribed hyperhydrosis
Reported association with:
Blue rubber bleb nevus
Burning feet syndrome (Goplan's)
Gustatory sweating associated with:
Herpes zoster (shingles)
Auriculotemporal or Frey's syndrome
Lacrimal sweating (due to postganglionic sympathetic deficit, often
seen in Raeder's syndrome)
Aluminium chloride is used in regular antiperspirants. However,
hyperhydrosis sufferers need solutions or gels with a much higher
concentration to effectively treat the symptoms of the condition.
These antiperspirant solutions or hyperhydrosis gels are especially
effective for treatment of axillary or underarm regions. Normally it
takes around three to five days to see the results. The main
secondary effect is irritation of the skin. For severe cases of
plantar and palmar hyperhydrosis, there is some success using
conservative measures such as higher strength aluminium chloride
antiperspirants. The Canadian Hyperhidrosis Advisory Committee
has published treatment guidelines for focal hyperhidrosis based on
evidence based clinical support. It recommends an aluminium chloride
hexahydrate salicylic acid gel as initial treatment for axillary,
plantar and palmar hyperhidrosis
Injections of botulinum toxin type A, (Botox, Dysport) are used to
block neural control of sweat glands. The effects can last
from 3–9 months depending on the site of injections. This
procedure used for underarm sweating has been approved by the U.S.
Food and Drug Administration (FDA).
Several anticholinergic drugs reduce hyperhidrosis. Oxybutynin
(brand name Ditropan) is one that has shown promise, although
it has important side effects, which include drowsiness, visual
symptoms and dryness in the mouth and other mucous membranes. A time
release version of the drug is also available (Ditropan XL), with
purportedly reduced effectiveness. Glycopyrrolate (Robinul) is
another drug used on an off-label basis. The drug seems to be almost
as effective as oxybutynin and has similar side-effects. Other
anticholinergic agents that have tried to include propantheline
bromide (Probanthine) and benztropine (Cogentin).
Sweat gland removal or destruction is one surgical option available
for axillary hyperhydrosis. There are multiple methods for sweat
gland removal or destruction such as sweat gland suction,
retrodermal currettage, and axillary liposuction, Vaser, or Laser
Sweat Ablation. Sweat gland suction is a technique adapted from
The other main surgical option is endoscopic thoracic sympathectomy
(ETS), which cuts, burns, or clamps the thoracic ganglion on the
main sympathetic chain that runs alongside the spine. Clamping is
intended to permit the reversal of the procedure. ETS is generally
considered a "safe, reproducible, and effective procedure and most
patients are satisfied with the results of the surgery".
Satisfaction rates above 80% have been reported, and are higher for
children. The procedure causes relief of excessive hand
sweating in about 85-95% of patients. ETS may be helpful in
treating axillary hyperhidrosis, facial blushing and facial
sweating; however, patients with facial blushing and/or excessive
facial sweating experience higher failure rates, and patients may be
more likely to experience unwanted side effects.
ETS side effects have been described as ranging from trivial to
devastating. The most common secondary effect of ETS is
compensatory sweating, sweating in different areas than prior to the
surgery. Major drawbacks related to compensatory sweating are seen
in 20–80%. Most people find the compensatory sweating to
be tolerable while 1–51% claim that their quality of life decreased
as a result of compensatory sweating." Total body perspiration
in response to heat has been reported to increase after
Additionally, the original sweating problem may recur due to nerve
regeneration, sometimes within 6 months of the
Other side effects include Horner's Syndrome (about 1%), gustatory
sweating (less than 25%) and on occasion very dry hands (sandpaper
hands). Some patients have also been shown to experience a
cardiac sympathetic denervation, which results in a 10% lowered
heartbeat during both rest and exercise; leading to an impairment of
the heart rate to workload relationship.
Lumbar sympathectomy is a relatively new procedure aimed at those
patients for whom endoscopic thoracic sympathectomy has not relieved
excessive plantar (foot) sweating. With this procedure the
sympathetic chain in the lumbar region is clipped or divided in
order to relieve the severe or excessive foot sweating. The success
rate is about 97% and the operation should be carried out only if
patients first have tried other conservative measures. This type
of sympathectomy is no longer considered controversial in regards to
hypotension and retrograde ejaculation. The development of
retrograde ejaculation, inability to maintain erection and
hypertension as a result of this surgery appears to be rare to
non-existent; journal articles describing the technique and case
reports suggest that none of 18 men undergoing the procedure at two
separate surgical units experienced sexual disability following
surgery, while no mention is made of hypertension or sexual
disabilities occurring in female patients.
Percutaneous sympathectomy is a related minimally invasive procedure
similar to the botulinum method, in which the nerve is blocked by an
injection of phenol. The procedure allows for temporary relief
in most cases. Some medical professionals advocate the use of this
more conservative procedure before the permanent surgical
Iontophoresis was originally described in the 1950s, although the
exact mode of action remains elusive. The affected area is
placed in a device that has two pails of water with a conductor in
each one. The hand or foot acts like a conductor between the
positively- and negatively-charged pails. As the low current passes
through the area, the minerals in the water clog the sweat glands,
limiting the amount of sweat released. Some people[who?] have seen
great results while others[who?] see no effect. The device can be
painful (pain is usually limited to small wounds and over time the
body adjusts to the procedure) and the process is time-consuming.
The device is usually used for the hands and feet, but there has
been a device[clarification needed] created for the axillae (armpit)
area and for the stump region of amputees.
Prognosis and impact
Hyperhidrosis can have physiological consequences such as cold and
clammy hands, dehydration, and skin infections secondary to
maceration of the skin. Hyperhidrosis can also have devastating
emotional effects on one’s individual life.
Affected people are constantly aware of their condition and try to
modify their lifestyle to accommodate this problem. This can be
disabling in professional, academic and social life, causing
embarrassments. Many routine tasks become impossible chores, which
can psychologically drain these individuals.
Excessive sweating or focal hyperhidrosis of the hands interferes
with many routine activities, such as securely grasping objects.
Some focal hyperhidrosis sufferers avoid situations where they will
come into physical contact with others, such as greeting a person
with a handshake. Hiding embarrassing sweat spots under the armpits
limits the sufferers' arm movements and pose. In severe cases,
shirts must be changed several times during the day. Additionally,
anxiety caused by self-consciousness to the sweating may aggravate
the sweating. Excessive sweating of the feet makes it harder for
patients to wear slide-on or open-toe shoes, as the feet slide
around in the shoe because of sweat.
Some careers present challenges for hyperhidrosis sufferers. For
example, careers that require the deft use of a knife may not be
safely performed by people with excessive sweating of the hands. The
risk of dehydration can limit the ability of some sufferers to
function in extremely hot (especially if also humid) conditions.
Even the playing of musical instruments can be uncomfortable or
difficult because of sweaty hands.
Focal hyperhidrosis is estimated at 2.8% of the population of the
United States. It affects men and women equally, and most
commonly occurs among people aged 25–64 years. Some may have been
affected since early childhood. About 30–50% have another family
member afflicted, implying a genetic predisposition.
In 2006, researchers of Saga University in Japan reported that
primary palmar hyperhidrosis locus maps to 14q11.2–q13.