Hyperhidrosis causes: what new research says about overactive sweat nerves

New research: hyperhidrosis causes may start in the nerves

In a study published in Science Advances on Jul 17, 2026, researchers sequenced families with inherited primary hyperhidrosis and found rare variants in SCN10A, the gene for a nerve sodium channel called NaV1.8. Mice engineered with one of these variants sweated excessively, and the channel was found in sympathetic nerve cells that help control sweating (Science Advances; Johns Hopkins Medicine).

Senior author Malcolm Brock, M.D., said the variant “essentially turns up the volume on the nerve signals that stimulate sweating.” In the mice, excessive sweating could be reduced with drugs that block sodium-channel activity. The researchers say some cases may be driven by the sweat glands themselves and others by the nervous system, and that future work must validate the findings in human tissue.

What the new Australian survey adds

The survey, published in the Australasian Journal of Dermatology on Oct 30, 2026 and reported by Dermatology Republic on Nov 11, asked 3,000 adults about their sweating. 156 people (5.2%) reported excessive or abnormal sweating; 41% said it began before age 14, 61% had it daily, and 65% rated it severe (Dermatology Republic; AJD).

Underarms were the most common site (68%), followed by palms (41%), soles (38%) and the head or face (26%). Only 49% had talked to a health professional and 27% had a formal diagnosis. The results are self-reported, and diagnoses were not confirmed by examination.

Why researchers say hyperhidrosis causes are still unclear

A 2026 review by Alexander Shayesteh in Acta Dermato-Venereologica links primary hyperhidrosis to autonomic (sympathetic) nerve dysregulation. It suggests that changes seen in sweat glands may be adaptations to constant nerve stimulation, and that genetic differences may help explain why severity varies (Acta Dermato-Venereologica).

The review also notes that reported prevalence varies widely between studies and calls for standardized diagnostic frameworks and better long-term research. That is why a dermatologist’s diagnosis matters more than any single study.

Underarm sweating and antiperspirants

For underarm sweating, treatment often starts with an antiperspirant. AAD notes that an antiperspirant temporarily blocks sweat glands, that non-prescription antiperspirants are only effective for mild hyperhidrosis, and that many patients need a prescription antiperspirant (AAD). In the Australian survey, prescribed topical aluminium chloride was the most commonly reported treatment (61%).

Maxim Ulti-Dri lists 15% aluminum chloride and is a topical underarm antiperspirant. It does not change the underlying cause of hyperhidrosis, and none of the research on this page tested Maxim.