Do Polio Survivors Sweat too Much, too Little or “Just Right?”

A Bruno Byte
From Richard L. Bruno, H.D, PhD
Director, International Centre for Polio Education

Question:

I've developed a problem where I sweat so much, even in winter, that I can soak my clothes. Sweating make me even colder than my usually cold, purple feet. Is my sweating a post-polio thing?

Answer:

The poliovirus damaged the brain stem nerves that control body temperature – those of the sympathetic nervous system - the part of the autonomic (i.e., “automatic”) system that should cause veins and arteries to constrict when you're too cold and open when you're too hot to radiate heat away from your skin. The sympathetic nerves also control sweating, which cools your body down by evaporation when opening up arteries doesn't “dump” enough heat by radiation.

The reason polio survivors have cold and purple "polio feet" is that there isn't a signal from the brain stem to tell blood vessels to constrict. So hot blood flows to the arteries near the surface of the skin, heat in the blood radiates away from your body and your skin gets cold, passively making the veins clamp down, trapping purple blood in the little veins and, voilà, “polio feet.”

The mechanism of sweating was one that I studied fairly extensively (for example in Parkinson's patients) before ever seeing a polio survivor with PPS. Given the inability of arteries to constrict, I would have expected poliovirus damage to the sympathetic nervous system to cause polio survivors to sweat too little. Over the course of 35 years I have not seen a polio survivor sweat too little and, for example, be overcome by the heat, let alone see one who was sweating too much. So while I studied blood flow and the effects of cold on polio survivors a lot, I didn't study sweating at all! I should say that in our first National Post-Polio Survey in 1985, about 1/3 of polio survivors said that they were adversely affected by the heat. But that would be caused by too little sweating, not too much.

Excessive sweating (called “hyperhydrosis”) is genetic in as much as 3% of the population, is seen under your arms, on the palm of your hands or soles of your feet, and can be caused by anxiety or by some medications. However, if you’re sweating too much in one large area (like your chest or back) or all over your body there could be an underlying treatable cause: Diabetes, an overactive thyroid, gout, rheumatoid arthritis, lymphoma an infection (e.g., Tuberculosis) or my old friend, Parkinson’s disease.

As always, don't assume too much (or too little) sweating is a PPS symptom. Tell your doctor and look for a treatable cause.