BackgroundIn Asia, axillary hyperhidrosis is a frequent problem for many people, and the consequent excessive sweating can seriously affect many aspects of daily life and even lead to mental disorders. Microwave therapy is a new, non-invasive treatment method for axillary hyperhidrosis, whose energy and long-term effectiveness still needs to be clinically validated. ObjectiveThe aim of this study was to evaluate the clinical efficacy, safety, histological changes, and psychological status of microwave devices in the treatment of axillary hyperhidrosis and osmidrosis. MethodWe conducted a prospective self-controlled study in a top-tier Chinese hospital. After a 5/5 energy treatment session, a skin biopsy was taken to observe histological changes both before and after treatment. An iodine starch test was used to determine the sweating range. We evaluated symptoms of improved efficacy using the Hyperhidrosis Disease Severity Scale (HDSS) and assessed changes in life status with the DLQI. In the case of concurrent underarm odor, odor-5, VAS, and Young-Jin Park grading were used to assess odor relief. The effect of odor on psychology was assessed by using a psychological status symptom checklist (scl-90). The study period was 1 year. ResultsWe observed 20 patients in this study. Of those, 90% met the primary treatment endpoint of a decrease in axillary hyperhidrosis symptomatology to below grade 2 on the HDSS score (p < 0.001). Furthermore, 75% of patients achieved a treatment endpoint of at least 50% reduction in VAS (p < 0.001). 70% of patients achieved a treatment endpoint of at least 50% reduction in odor-5 (p < 0.001). The iodine starch test showed that the region decreased 99% from the baseline to 12 months after follow-up had ended (p < 0.001). Eight patients volunteered to undergo histological examination; their average light density of immunohistochemistry decreased from 1.04 (0.4-2.11) to 0.07 (0.04-0.46; p < 0.05). The immunohistochemical positive number for sweat glands was initially 104 (59.75-132.5) but was 41.5 (29.75-62) after the procedure. None of the patients experienced any serious adverse reactions. ConclusionThe treatment demonstrated high effectiveness, safety, and short-lived adverse reactions.