Sweating Symptoms and Causes

We will discuss the causes of two types of hyperhidrosis:

Focal (Localized) hyperhidrosis – Focused in one area (Hands, Feet, Armpit)
Generalized hyperhidrosis – Over the entire body

Focal
The most likely cause of excessive focal (isolated to specific parts of the body such as hands, feet, or armpit) hyperhidrosis is genetics. Medical Scientists have successfully linked hyperhidrosis to heightened activity in the sympathetic nervous system, which is genetically determined.¹

The same gene that causes palmar hyperhidrosis (excessive hand sweating) is most likely responsible for excessive foot sweating (plantar hyperhidrosis) as well. This gene causes heightened activity in the sympathetic chain. Interestingly, it is normal that the manifestation of palmar hyperhidrosis (excessively sweaty hands) will appear earlier in life than plantar hyperhidrosis.

The term hyper sympathetic activity is an accurate terminology to describe what happens when excessive sweating occurs with focalized hyperhidrosis. This heightened activity is in the sympathetic chain (located within the chest cavity of the body). This activity has nothing to do with motoric or sensory functions, which are part of the voluntary nervous system.

A simple explanation is that hyper sympathetic activity (excessive sweating) involuntarily occurs within the sympathetic chain and cannot be controlled voluntarily by an individual as can our motor or sensory functions (aspects of behavior, motor actions and sensory processing). In other words, your excessive hand sweating is not something you can control yourself.

In cases of palmar hyperhidrosis (hand sweating), the responsible sympathetic ganglia that receive the signal for that abnormal activity are located within the upper part of the chest cavity. In cases of plantar hyperhidrosis (foot sweating), the responsible sympathetic ganglia that receive the wrong signal are located within a section of the lumbar sympathetic chain. This is a simplified way of explaining the complex anatomical and neurological basis for excessive local hyperhidrosis (Excessive sweating of the Hands, Feet & Armpits).

Learn more about ETS or ELS surgery for focal hyperhidrosis of the hands and feet.

Generalized Hyperhidrosis
In cases with generalized hyperhidrosis, excessive sweating can appear in most parts of the body. It can happen on the face, body, and extremities. In those cases, it is possible that patients have some other systemic problems such as obesity, febrile illnesses, some sort of neoplastic disease (cancers), or some endocrinological disorders such as overactive thyroid gland. Side effects of specific medications may also be a cause for generalized hyperhidrosis.

A search for a specific reason to explain excessive sweating in general can be a challenge. A cause cannot be found in every case, in which case the diagnosis of idiopathic hyperhidrosis can be applied to those cases. Idiopathic meaning “unknown.” Cases of generalized hyperhidrosis usually appear in the adult population. Regarding treatment, we suggest you work with your physician or dermatologist to first identify the cause (if possible) of your excessive generalized sweating and treat the underlying cause (if determined). If “unknown” you can discuss conservative treatments with your physician. We do not treat generalized hyperhidrosis surgically.