Humidity Makes MS Symptoms Worse

The vast majority of us are affected by high humidity

Summer heat can affect people with MS.
Summer heat can affect people with MS. Valentine/Getty Images

I’ve often wondered if humidity played a role in how bad my multiple sclerosis symptoms felt on a given day. After all, it seems that we only mention “humidity” in conjunction with hot days, and heat intolerance is one of the most common symptoms of MS.

I have my own opinions on the matter, but I asked for reader input and got a number of responses:

“I vacation in Arizona almost yearly and I’ve noticed how much better I feel there.

I think there is definitely a link between high humidity and MS symptoms.”

“Humidity DEFINITELY affects me. Yesterday it was 93 degrees but dry, so no ZINGERS, as I like to call them. Today, it’s 75 degrees outside, but drippingly humid, so I feel HEAVY and SLOWWWW.”

“I agree, humidity changes everything, from eyes to legs, pain and stiffness – vision blurred – eye pain – and the entire body changes, along with fatigue. And yes, today it was 93 and no humidity, finally a day of fun in the sun, and no side effects.”

“Buy a dehumidifier and put it in your house. Put one in the bedroom and one in the middle of your house. Make sure your A/C is working properly. Most of the cooling is in the dehumidification process. It truly makes sense. The humidity acts as yet another medium in which to transmit electrical impulses. It is like stepping in a puddle and operating a piece of electrical equipment.

You become the ‘ground.’”

“Humidity affects everybody, not just people with MS. Admittedly not as much. I live in east Texas where the summers are extremely hot and humid. When the humidity goes up, folks slow down. I spent much of my life in construction, humid days were always tougher than the drier ones.

I relished the hot, dry days in Saudi on jobs there. I’ve been diagnosed 13 years now (1997), now when the humidity goes up, I slow WAY DOWN.”

“I live in a dry climate, so my only experiences with humidity are when I am on vacation. I am certainly worse when it is humid – but I also know that our bodies cannot cool ourselves as well when it is humid. Because our sweat (anyone’s, not just those with MS) does not evaporate, we feel hotter and our core temperature does go up faster. This is why when a heat index is calculated, the humidity will add degrees – it feels hotter, and to our bodies, IS hotter. So it makes sense we would be worse on a hot humid day than a hot dry day.”

“I live in Phoenix but just vacationed in NY and along the eastern seaboard. The humidity definitely affected my MS symptoms far more than 110+ heat in Phoenix does.”

“I find that in humid conditions, I tend to have vision and pain issues. My vision blurs in and out until I get somewhere cool with a lower humidity. As for my pain issues, sometimes, it seems as if the humidity wants to “sit” in a specific area making me seriously stiff in that area–my back, my legs, my feet and when it does, the pain can be numbing, horrendous, and I can feel as if that part is on fire.

It also makes me feel really bad fatigue.”

“I agree with all of you about the humidity. I normally don’t have much cognitive dysfunction, but yesterday and today I feel like an airhead! I feel sluggish and tired, as well. My balance is my major issue with MS and that’s much worse, too. So yes, I think the heat and humidity are definitely a factor in my MS symptoms.”

Bottom Line: You get the picture. For the most part, people with MS do not like humidity. One person said that humidity affected them when it got over 30%, while a couple of other people mentioned that it was 50 to 60% humidity that was the problem.

There were over 100 of these comments and I only heard from seven people who said that the humidity did not affect them. Interestingly, six of these people believed that it was the barometric pressure, and not the humidity, that was the culprit in weather-related changes in MS symptoms. I’ll have to look into that.