Disorders of Sweating

Original Editor - Kapil Narale

Top Contributors - Kapil Narale and Uchechukwu Chukwuemeka  

Disorders of Sweat Gland Function[edit | edit source]

Some certain diseases or disorders can alter the amount that a person sweats. Some of these are explained below[1]:

A chronic condition of Cystic Fibrosis would experience more sweating of Na+ and Cl- content due to a genetic deficiency or absence of functioning CFTR (cystic fibrosis transmembrane conductance regulator), which would lead to lower reabsorption rates of Na+ and Cl- in the sweat ducts. [1]

A chronic condition of Addison’s Disease would experience more sweating than normal of Na+ and Cl- due to an impaired adrenal cortex function, which would lead to lower reabsorption rates of Na+ and Cl- in the sweat ducts. [1]

A chronic condition of Diabetes Mellitus would cause decreased sweating with Type I and Type II diabetes mellitus. Possible mechanisms could be related to autonomic neuropathy and decreased heat sensitivity, decreased maximal sweat rate, and/or a reduced number of active sweat glands. There is also an inhibited ability to control the heat, especially in higher temperatures and in less fit individuals. [1]

A chronic condition of Multiple Sclerosis would cause decreased sweating due to lesions within the central nervous system, which would lead to a decreased sweat output per gland. [1]

A chronic Spinal Cord Injury would cause decreased or absence of sweating in the non-sensory skin, which can be due to disruption in neural pathways involved in central and peripheral control of sweating. Contrarily, there is an increase in sweating in the sensory skin superior to the spinal lesion. [1]                 

A chronic condition of severe Burns and Skin Grafting would cause decreased or absence of sweating in the burned area, due to the removal of dermal and epidermal layers, including the sweat glands. Even as skin grafts heal, there is still a disruption in the ability to sweat. [1]

An acute condition of Sunburn would cause decreased sweating in artificially induced mildly sunburned skin. [1]

An acute condition of Miliaria Rubra (heat rash or prickly heat) would cause decreased sweating due to pore occlusion via keratin plugs, which would cause mechanical blockage of sweat smoothly flowing onto the skin surface. This can be caused by increased humidity, which would cause excess sweat, on the skin surface, for longer periods. [1]

An episodic condition of Atopic Dermatitis (eczema) would cause decreased sweating on the surface of the skin due to blockage of sweat pores by keratin plugs, sweat leaking into dermal tissue around the glands, and/or histamine-induced sweat prevention. Sweat glucose concentration can be higher than expected with acute atopic dermatitis. [1]

A chronic condition of Anhidrotic Ectodermal Dysplasia would cause decreased or absence of sweating due to a small genetic disturbance, or eliminated sweat glands throughout the body. These patients can especially experience heat intolerance. [1]

A chronic or episodic condition of Primary Hyperhidrosis will produce a greater amount of sweat, primarily affecting one or both axillae, palms, soles, and the head and face (craniofacial areas). This would be induced by neurogenic overactivity of sweat glands, which would otherwise be normal. This occurrence would be from genetic factors. [1]

A chronic or episodic condition of Secondary Hyperhidrosis will produce a greater amount of sweat on one or both sides, due to an underlying physiological condition (fever, pregnancy, menopause), pathology (malignancy, infection, cardiovascular disease, Respiratory failure, endocrine/metabolic, neurologic or psychiatric disorders), Obesity, Substance abuse or medication. [2]

Long-term Tattoo usage can cause decreased sweating rate and higher sweat content of Na+ from pharmacologically-induced local sweating, compared to non-tattooed skin. [1]

With acute or chronic use of Medications, chemicals such as Antimuscarinic anticholinergic agents, carbonic anhydrase inhibitors, and tricyclic antidepressants can cause generalized hypohidrosis. As mentioned above, hyperhidrosis is a factor in altered sweating and can be caused by cholinesterase inhibitors, SSRI (selective serotonin reuptake inhibitors), opioids, and TCA (tricyclic antidepressants). [1]

It can be noted that patients with diabetes mellitus, multiple sclerosis, spinal cord injury, and anhidrotic ectodermal dysplasia can have a severe impairment of thermoregulation. [1]

Salt conservation by the sweat gland becomes relevant in patients with reduced ion resorptive capacities due to a genetic deficiency or malfunctioning CFTRs, in cystic fibrosis, or impaired adrenal cortex functioning, in Addison’s disease. These patients may be more prone to electrolyte imbalances. [1]

Sweating Induced Deficiencies[edit | edit source]

Hyponatremia - a condition where the plasma Na+ concentration is less than 135mmol/L. This can be life-threatening based on the plasma Na+ dilution, <125-130mmol/L, and how quickly it decreases. Similar to osmotic activity, the decreased solute concentration in plasma enhances the movement of water from the extracellular to the intracellular space, causing inflammation in the form of swelling in the brain and/or congestion in the lungs. [1]

This can occur in healthy athletes or even in the clinical population. [1]

Plasma Na+ concentration is responsive to changes in body water. Therefore, the main cause of hyponatremia is an increase in body mass due to hydration from water or hypotonic fluid, relative to body water loss. [1]

Plasma Na+ concentration is also somewhat responsive to changes in the mass balance of Na+ and K+, mainly from loss of electrolytes through sweat. Overhydration during an event greater than 4 hours can cause increased sweat Na+ losses, which can worsen losses of plasma Na+ concentrations. [1]

Hyponatremia is also associated with dehydration, in which a higher sweat Na+ loss is the main cause of a drop in plasma Na+ concentration. [1]

Someone's Na+ sweat concentration affects their risk for resulting with hyponatremia, when long-term thermoregulatory sweating is involved. [1]

Cases of 'salty sweat', increased sweat Na+ and Cl- concentrations, also need to be considered. Salty sweat can be seen in healthy individuals and individuals with cystic fibrosis. Despite the causes, it is seen that excessive electrolyte losses from sweating can facilitate Na+ and Cl- imbalances. [1]

Minerals[edit | edit source]

Two more critical minerals lost in sweat are calcium (Ca2+) and iron (Fe3+). It was mentioned by the International Olympics Committee that an increased loss of sweat may lead to suboptimal Fe3+ levels and therefore would require an external source. Sweat or dermal Ca2+ losses in athletes may lead to decreased bone mineral density by activating the parathyroid hormone during training. Despite this, sweat loss has a minimal effect on trace mineral and vitamin deficiencies. [1]

In a bout of 1-2 hours of exercise, the serum concentration of ionized calcium decreases, which leads to an elevation of parathyroid hormone, and facilitation of bone reabsorption. This would have consequences on athletes' bone mineral density throughout their season of training. A reason for this may be that an exercise-induced increase in parathyroid hormone is stimulated by sweat Ca2+ loss. [1]

Ca2+ supplementation can slow down increases in parathyroid hormone and stimulation of bone resorption during exercise, though the mechanism through which supplementation is facilitated is unrelated to the replacement of sweat Ca2+ loss. Contrarily, it is not probable that there is a large enough Ca2+ loss during exercise to affect homeostasis, since the decrease in serum ionized calcium concentration occurs in the first 15 minutes of exercise. [1]

Overall, there isn't a need for supplementation if an athlete or individual has a normal healthy diet. [1]

Inability to Sweat[edit | edit source]

Hypohidrosis or anhidrosis are terms used to describe when an individual is not able to, or no longer able to, sweat, due to dysfunctional sweat glands. This can occur in a certain area of the body, in various areas, or throughout the entire body. A large consequence of not being able to sweat is overheating of the body, which can cause heat stroke and such injuries and illnesses. [3]

This condition is difficult to diagnose and can often go unnoticed. [3] Hypohidrosis has many possible causes, which may be inherited from birth, or may occur later in life. This may occur as one age, or can even set in with conditions such as diabetes, as mentioned above. These conditions would worsen one's autonomic nerves, and accelerate any issues with the sweat glands. [3]

The following problems may cause hypohidrosis:

Nerve Damage[edit | edit source]

Nerve damage can impair the functioning of the sweat glands. Such conditions can include: [3]

Skin Damage and Disorders[edit | edit source]

Sweat glands can be severely damaged from severe burns. Other conditions that can damage sweat glands include: [3]

Medications[edit | edit source]

Certain medications, especially those known as 'anticholinergics', can induce reduced sweating. They have side effects such as sore throat, dry mouth, and reduction in perspiration. [3]

Inherited Conditions[edit | edit source]

It is possible to inherit a damaged gene, which would result in the malfunctioning of sweat glands. [3]

Hypohidrotic ectodermal dysplasia is an inherited condition, that causes people to be born with very few or no sweat glands. [3]

Symptoms[edit | edit source]

Symptoms of hypohidrosis can include:[3]

  • Very minimal sweating, even when others are sweating
  • Dizziness
  • Muscle cramps or Muscle weakness
  • A flushed appearance
  • Feeling overly hot

Hypohidrosis may be unnoticed unless you are vigorously active and become overheated due to minimal sweat or the absence of sweat.

Diagnosis[edit | edit source]

Certain tests that can be used to diagnose hypohidrosis include: [3]

  • Axon Reflex Test - small electrodes are used to stimulate the sweat glands, and the volume of sweat produced is measured
  • Silastic Sweat Imprint Test - indicates where you sweat
  • Thermoregulatory Sweat Test - the body is coated with a powder that changes colour in sweat areas. A chamber is used, which causes the body temperature to rise to a level that would induce sweat
  • Skin biopsy - some skin cells, and sweat glands, are removed to be analyzed under a microscope

Treatment and Prevention[edit | edit source]

If hypohidrosis only affects a small part of the body, it may not need such treatment. If it is due to an underlying condition, addressing or treating the condition will most likely minimize the symptoms of hypohidrosis. If it may be caused by the medications themselves, reducing or adjusting the medications may help with improving sweating. [3]

Hypohidrosis may not be prevented, but the symptoms of overheating can be minimized. Ideas would be to wear loose clothing, not overdress, stay inside when it's hot, and not overexert oneself in the heat. [3]

Simulating the effect of coolness by applying water or cool pads, simulates the effect of sweating. [3]

Here is a brief video about not being able to sweat, or the inability to sweat:

[4] While the above section discusses hypohidrosis, here is a video outlining 7 reasons for hyperhidrosis:

[5]

For an extension on the topic of sweat, check out these pages:

Here is a quick, very informative TedEd video on sweat, and its various components: [6]

References[edit | edit source]

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 Baker Lindsay B. Physiology of sweat gland function: The roles of sweating and sweat composition in human health. Temperature. 2019:6(3):211-259.
  2. Brazier Y. What is hyperhidrosis? 2023. Available from:https://www.medicalnewstoday.com/articles/182130#causes (accessed July 21 2023)
  3. 3.00 3.01 3.02 3.03 3.04 3.05 3.06 3.07 3.08 3.09 3.10 3.11 3.12 Healthline. Hypohidrosis (absent sweating). Available from: https://www.healthline.com/health/sweating-absent (accessed 21 June 2022)
  4. Life Noggin. What if You Never Sweat? Available from: http://www.youtube.com/watch?v=fxUQXR5vtUU [last accessed 7/7/2023]
  5. Medical Centric. 7 Reasons You Might Be Sweating A Lot. Available from: http://www.youtube.com/watch?v=nLGnghVPPP4 [last accessed 7/7/2023]
  6. TedEd. Why do we sweat? - John Murnan. Available from: https://www.youtube.com/watch?v=fctH_1NuqCQ&ab_channel=TED-Ed (accessed 24 June 2022).