Excessive sweating is one of the most visible aftereffects of a severe traumatic brain injury. The problem, unfortunately, is far from rare. For decades, studies indexed by the National Library of Medicine have been examining this condition, with estimates showing that this condition strikes roughly 8 to 33 percent of severe TBI patients. In acute stroke, one study found that sweating primarily occurs on the paralyzed side of the body in 55 percent of patients.*

Clinically recognized as paroxysmal sympathetic hyperactivity (PSH), the condition causes sudden, severe surges in the body’s fight-or-flight nervous system. Damage to the hypothalamus, the body’s thermostat, deepens the disruption. The “storm” occurs when the injured brain disconnects the brain’s inhibitory centers from its excitatory ones. Patients then erupt in surges of racing heart, spiking blood pressure, fever and drenching sweat.

Treatment leans heavily on medication. A 2026 trial at Zagazig University, a public university in Egypt, that is published in BMC Anesthesiology and found in the NLM-database, concluded that “prophylactic propranolol significantly reduces PSH incidence.” Physicians also prescribe medications that are typically used to treat different ailments: clonidine, gabapentin, morphine, baclofen, and botulinum toxin injections.

* Can the reverse happen? Yes. The same hypothalamic damage can leave survivors feeling persistently cold, or even dangerously hypothermic.