Sometime back on my YouTube channel We R Stupid , I made one of the most extensive video series on sweat. I gave the basics of sweating , and the myths and research associated with sweating . But eventually, a lot of people questioned me about ‘sweaty palms’, which I did not cover.

Let’s get the basic concept of hyperhidrosis, which is extremely vital to know before we know about sweaty palms .

Hyperhidrosis is the excessive excretion of sweat above the quantity needed for thermoregulation. Sensors in our skin can detect changes in temperature and relay signals to our brain when we exercise or when it is hot outside. In turn, our brain signals the sweat glands that it’s time to start producing sweat. In people with hyperhidrosis, it is believed that overstimulation of nerve fibres in sweat glands causes excessive sweating.

Acc. to a 2016 study in the Journal of Neurology & Neuromedicine, Swedish research team led by Alma Rystedt , Hyperhidrosis is a social, emotional and occupational disability. Patients with hyperhidrosis suffer an extremely negative impact on their quality of life.

Hyperhidrosis are of the following types: face and scalp (craniofacial hyperhidrosis), palmar region (palmar hyperhidrosis), armpits (axillary hyperhidrosis), inguinal region (inguinal hyperhidrosis) and plantar regions (plantar hyperhidrosis).

Acc. to a 2009 study in the German journal Deutsches Ärzteblatt International, led by Tanja Schlereth, there are two types of hyperhidrosis, Focal & Generalized hyperhidrosis.

Generalized hyperhidrosis affects the entire body and is caused, by:

• infections,

• endocrine disturbances and changes (hyperthyroidism, hyperpituitarism, diabetes, menopause and pregnancy, carcinoid syndrome, acromegaly)

• neurological disorders (e.g., parkinsonism)

• malignancies (myeloproliferative syndromes, Hodgkin’s disease)

• medication (e.g., antidepressants)

• intoxication

• withdrawal of alcohol or other substances

Focal hyperhidrosis develops “idiopathically” in otherwise healthy persons. The onset is mostly in puberty. There does seem to be a genetic predisposition because patients have a positive family history. Primary hyperhidrosis affects mainly the axillae (armpit), but the feet, hands, and face can also be affected; often, several areas are affected.

Hyperhidrosis is a complex dysfunction of the sympathetic and parasympathetic nervous system. Patients are often subject to severe psychosocial problems. They often avoid shaking hands or have unwanted sweat patches under their arms. Secondary focal hyperhidrosis is the result of central or peripheral neuronal defects. Peripheral causes are neuropathies—e.g., diabetic neuropathy.

Schlereth & team suggests that, especially in focal sweating disorders, Minor’s starch iodine test is appropriate. Iodine solution is applied to the skin and starch powder is applied on top of this. As soon as those substances are in contact with sweat, they assume a violet colour. The distribution pattern of the colour (or absence of it) often allows conclusions about the cause of the focal sweating disorder.

Treatment options include topical medications, oral medications, surgical procedures, or botulinum toxin injection.

When we talk about ‘sweaty palms’ it is medically termed as ‘Palmar Hyperhidrosis’. Acc. to a 2016 study in the Brazilian journal Anais Brasileiros De Dermatologia, by a research team, led by Flavio R. Romero , the natural history of sweaty palms is the onset of excessive sweating in childhood for mostly individuals, manifesting itself more strongly in ages of hormonal and sexual maturation during adolescence. Improvement after the fourth decade of life is common, and cases that persist after the fifth decade of life are rare. There seem to a genetic reason behind development of sweaty palms .

Romero & team found that, the episode of sweating has abrupt onset, related or not with emotional stressful events, and presents more intensely on the palms and fingers and less intensely in the posterior regions of the hands. Rapidly, the hands are wet by the droplet detachment, and in some cases there may be swelling of the fingers. The main diagnostic criteria include visible sweat, exaggerated and located, lasting at least six months, without apparent cause, and with at least two of the following characteristics: 

• Bilateral and symmetrical sweat

• Frequency: at least one episode per week

• Impairment in daily activities

• Age of the onset <25 years

• Presence of family history

• Absence of sweat during sleep

Palmar hyperhidrosis can be evidenced from the Minor test (starch-iodine), in which an alcoholic solution of iodine 2% is applied in the test area and subsequently starch (e.g. corn-starch) is sprinkled.

There can also be several secondary hyperhidrosis conditions, due to which palmar hyperhidrosis can develop:

•  Endocrine: hyperthyroidism, hypopituitarism, diabetes, menopause, hypoglycaemia, pregnancy, pheochromocytoma, carcinoid syndrome and acromegaly.

• Neurologic: Parkinson’s disease, spinal cord injury and stroke, vasovagal syndrome, hypothalamic hyperhidrosis, reflex sympathetic dystrophy.

• Neoplastic: tumours of the central nervous system (CNS), Hodgkin’s disease and myeloproliferative diseases, cancer of the thoracic cavity.

• Infectious: feverish conditions, tuberculosis and septicaemia.

• Drugs: fluoxetine, venlafaxine, doxepin, opioids, amitriptyline, insulin, nonsteroidal anti-inflammatory.

• Toxicity: alcoholism and substance abuse.

• Iatrogenic: postoperative compensatory sweating (sympathectomy, cardiac surgery).

Here are the suggested treatment options in the research:

• Astringent solutions: also called antiperspirants, they act on the opening of the sweat glands blocking the elimination of sweat. They are indicated for palmar hyperhidrosis of mild to moderate intensity. They should be applied preferably during night, two to three times a week. They have to be applied on a completely dry skin, and one should not fold/wrap their hands with antiperspirants on them, or it will lead to skin irritation.

• Iontophoresis: immersion of affected area in ionized solution with electric current of low voltage. It is suggested that ionic changes on the sweat glands cause temporary blockage of sweating, with improvement in symptoms for about four weeks. The major limitation of this method is the frequency of treatment, which should be from 30 to 40 minutes, daily, on the affected area, at least four times a week. It’s not entirely understood how or why iontophoresis works, but it’s believed that the electric current and mineral particles in the water work together to microscopically thicken the outer layer of the skin, which blocks the flow of sweat to the skin’s surface. Once this sweat output is blocked or interrupted, sweat production on the palms and soles is, often suddenly and dramatically, “turned off”.

• Anticholinergic drugs: they act as antagonists of muscarinic receptors of the sweat glands, competing with acetylcholine. The oxybutynin hydrochloride 5-10mg/day is one of the most used, with results considered promising. The effectiveness is dose-dependent, and often the adverse events are well tolerated, such as dry mouth, urinary retention, intestinal constipation, postural hypotension, dyspepsia, nausea and vomiting

• Botulinum toxin (Botox): it blocks the release of acetylcholine in neuroglandular junction, resulting in decreased impulse transmitted to the sweat gland. The symptoms resolution is maintained by about 6 months, requiring repeated applications. A disadvantage of this method is the painful condition that occurs during the application in some areas of the body, such as hands and feet. 

• Emerging therapies: fractional radiofrequency with microneedles, microwave therapy and use of high intensity focused ultrasound (HIFU).

• Thermolysis – Using targeted microwaves or lasers, this treatment causes the destruction of sweat glands through localized heating.

• An operation to surgically remove the sweat glands from the underarms or palms of the hands. Currently, the video-assisted thoracoscopic sympathectomy (VATS) is considered the most effective treatment for PH for presenting long lasting functional results, being considered the best therapeutic option.