Multiple sclerosis (MS) is an autoimmune disease that affects the central nervous system. It can cause a wide range of symptoms, and excessive sweating (hyperhidrosis) is one of them. In this article, we’ll take a look at the connection between MS and sweating, why it happens, and what can be done to manage it.
What causes sweating in MS?
There are a few potential reasons why MS can lead to excessive sweating:
- Damage to the nerves that regulate body temperature – MS causes damage to myelin, the protective covering on nerves. This includes the nerves that control temperature regulation. Disruption to these nerves can impair the body’s ability to control sweating.
- Heat sensitivity – Many people with MS experience worsening symptoms when their body temperature increases even slightly. This is known as a pseudoexacerbation. Their nerves become overloaded and sweat production ramps up in an effort to cool the body down.
- Medications – Some medications used to treat MS symptoms can cause increased sweating as a side effect. These include anticholinergic medications like oxybutynin.
- Autonomic dysfunction – MS can sometimes affect the autonomic nervous system, which controls involuntary functions like sweating, heart rate, and blood pressure. Autonomic dysfunction makes it harder for the body to regulate these functions.
What types of sweating are connected to MS?
There are a few categories of excessive sweating that people with MS often experience:
- Heat-induced sweating – Also called gustatory sweating, this involves sweating brought on by an increase in body temperature, spicy foods, or warm environments.
- Emotional sweating – Sweating episodes triggered by emotions like anxiety, stress, embarrassment, or laughter.
- Night sweats – Intense, drenching sweating that occurs during sleep, often waking the person up.
- Primary focal hyperhidrosis – Excessive sweating that affects specific parts of the body like the underarms, hands, feet, face, or head.
What areas of the body are affected?
In MS, sweating can occur all over the body. However, it may be more pronounced in certain areas, including:
- Underarms
- Hands
- Feet
- Face
- Scalp
- Groin
- Chest
- Back
This localized sweating is connected to the autonomic dysfunction that can happen with MS. The nerves supplying specific areas can become overactive and trigger excessive sweating.
How much sweating is considered excessive?
There’s no definitive measure for how much sweating is considered excessive. But here are some signs that sweating may be abnormally high:
- Sweating 4 or more times per week without an obvious trigger like heat or exercise
- Sweat dripping from the hands, armpits, or face on a regular basis
- Sweating that leaves clothing or bed sheets noticeably wet
- Discoloration or damage to clothing from frequent sweating
- Dehydration or electrolyte imbalances caused by excessive sweating
- Sweating that interrupts daily activities or sleep
Keeping track of sweating episodes in a symptom journal can help identify when it becomes excessive or disruptive.
How common is sweating as a symptom?
Studies show that around 1 in 5 people with MS experience some degree of excessive sweating:
- A 2021 study found that 21% of 120 MS patients reported excessive sweating.
- In a 2017 survey of over 700 MS patients, 19% said they struggled with increased sweating.
- Up to 27% of people with MS may experience gustatory sweating with spicy or hot foods.
So while not everyone with MS deals with hyperhidrosis, it appears to impact a substantial minority.
Are certain MS types more prone to sweating?
Those with progressive MS seem more likely to experience increased sweating compared to relapsing-remitting MS. In one study:
- 27% of secondary progressive MS patients had excessive sweating.
- 22% of primary progressive MS patients had excessive sweating.
- Only 13% of relapsing-remitting MS patients had excessive sweating.
This may be because progressive MS leads to worsening nerve damage over time. The body’s temperature regulation becomes increasingly impaired.
Can sweating predict MS progression or severity?
A few studies suggest that sweating could be linked to MS disease progression:
- One study found patients with gustatory sweating had more advanced MS and disability than those without it.
- Another study showed patients with severe night sweats had higher MS severity scores than those with mild or no night sweats.
More research is needed to confirm if sweating can serve as a marker of MS progression. But these early findings suggest it may correlate with worsening nerve damage.
Can sweating worsen MS symptoms?
Excessive sweating itself does not make MS worse or cause permanent nerve damage. However, it can temporarily exacerbate symptoms like:
- Fatigue – Dehydration and night sweats disrupt sleep, leading to low energy.
- Heat sensitivity – Getting overheated from sweating episodes can impair nerve function.
- Bladder problems – Sweating and increased thirst can cause urgency and frequency.
- Cognitive difficulties – Disrupted sleep from night sweats reduces mental sharpness.
Managing sweating and staying cool may help minimize these symptom flares.
When does sweating tend to improve or worsen?
MS is unpredictable, so sweating patterns can vary over time. But here are some general trends:
- Worsens during MS exacerbations or disease progression, as nerves become more damaged.
- Improves with medications or supplements that reduce nerve inflammation.
- Worsens in hot weather, with fever, during rigorous exercise, or in stressful situations.
- Improves with cooling strategies like air conditioning, cold beverages, and breathable clothing.
Keeping detailed symptom records can help identify individual triggers and patterns.
Tips for managing sweating with MS
While sweating can’t be cured, it can often be well-managed. Some tips include:
- Staying cool with air conditioning, fans, cold drinks, and frequent cooling breaks.
- Avoiding hot environments, spicy foods, excess caffeine, and stress when possible.
- Using antiperspirants and sweat-wicking clothing in problem areas.
- Trying prescription antiperspirants like Drysol if over-the-counter options are ineffective.
- Getting good sleep hygiene to reduce night sweats.
- Discussing prescription medications that may help if sweating is severe.
- Using absorbing products like sweat pads, moisture-wicking sheets, and shoe inserts as needed.
- Staying hydrated and replenishing electrolytes after heavy sweating.
Your MS healthcare provider can help develop an individualized plan to manage sweating and improve your quality of life.
When to see a doctor
Consult your MS doctor or neurologist if you experience:
- Severe, daily sweating that interferes with work, school, or relationships
- Night sweats that regularly disrupt sleep
- Lightheadedness, heart palpitations, or muscle cramps after sweating episodes
- Swelling or changes in sweating patterns that may indicate a new MS lesion
- Prescription antiperspirants or other hyperhidrosis treatments that are ineffective
A doctor can check for underlying causes, assess your symptoms, and adjust your treatment plan accordingly.
Takeaway
Excessive sweating is a relatively common symptom for those with multiple sclerosis. It can occur all over the body or target specific areas more intensely. Sweating tends to be worse with heat, anxiety, and disease progression. While it may temporarily aggravate other MS symptoms, hyperhidrosis itself does not cause permanent nerve damage or make the condition worse. With proactive cooling and sweat management strategies, most people can minimize sweating episodes and their impact.