Living with an autoimmune disorder like myasthenia gravis (MG), you may notice times when you feel better and times when you feel much worse. When symptoms like muscle weakness, drooping eyelids, or double vision become more severe, it’s called a flare-up. (Flare-ups are different from a myasthenic crisis, which may cause life-threatening shortness of breath and requires emergency treatment.)

Several factors can trigger symptom flare-ups in myasthenia gravis. Identifying your specific triggers can help you manage your condition better. Once you know what causes your flare-ups, you can take steps to avoid them. This process may require some trial and error.

Here are some common triggers to pay attention to. Many of them can be avoided to help keep symptoms under control.

1. Stress

Stress can trigger myasthenia gravis flares, leading to increased muscle weakness. When stressed, your muscles tense up — similar to the effects of strenuous exercise — leaving them extra weak.

Some members of MGteam have observed this correlation. “I have noticed that there is a correlation between stress events and MG problems,” one member reported.

If stress affects your MG symptoms, managing that stress can help. As one MGteam member said, “My top priorities in lifestyle adjustments were to identify stressors and positively modify them to remove stress.”

For some people, managing stress may start with accepting the new normal of life with myasthenia gravis and asking for support when it’s needed.

2. Surgery

Having any sort of surgery can also worsen myasthenia gravis, though health experts aren’t sure why. A member of MGteam who experienced this said, “Been struggling this week with MG. … Don’t know if this surgery I had has set me back.”

If you need surgery, inform all your doctors about your myasthenia gravis. They can help you weigh the pros and cons and create a plan to manage potential symptoms. Similarly, for dental procedures, ensure your dentist or oral surgeon is familiar with myasthenia gravis and its treatments.

3. Infection

Some infections can also worsen myasthenia gravis symptoms. This reaction isn’t limited to a specific kind of infection, and it’s a common trigger among MGteam members. One member, after developing a urinary tract infection (UTI), reported, “My MG symptoms creeped up again!”

Another added, “I had one myasthenic crisis 14 years ago due to an infection.”

To help prevent infections, consider getting regular immunizations. However, consult your MG specialist first, especially if you’re on immunosuppressive medication, as you may need to avoid live vaccinations (vaccines that use a weakened form of a virus or bacteria).

Follow standard advice to avoid infections, too. This means:

• Washing your hands frequently with soap and water
• Not sharing drinks or food with others
• Making sure the people around you cover their coughs and sneezes effectively
• Wearing a face mask to reduce the chance of infection, especially in crowded or enclosed spaces

If you’re concerned about catching something, limiting contact with others — especially during outbreaks or flu season — can significantly lower your risk.

4. Allergic Reactions

Some research suggests that people with allergies may be more likely to develop myasthenia gravis. Like MG, allergic reactions involve the immune system, so it makes sense that exposure to allergens could potentially trigger flares in some people. Anything that throws the immune system out of balance might increase the risk of a flare-up.

If you know what you’re allergic to, it’s best to avoid those allergens as much as possible. Ask your MG specialist whether it’s safe to take antihistamines — medications that block allergic responses — especially if you’re on other treatments for MG.

5. Pregnancy

Pregnancy brings many changes to the body — and for some people with myasthenia gravis, it can lead to worsening symptoms. Others may experience remission, which means symptoms temporarily disappear.

If you’re pregnant, it’s important to know when to contact your doctor. Let them know right away if your MG symptoms get worse — especially if you have trouble breathing. This could be a sign of a serious complication that needs urgent care to protect both you and your baby.

When in doubt, reach out. It’s always safer to ask for help early than to wait until things get worse.

6. Certain Medications

A variety of medications can worsen myasthenia gravis symptoms. These include drugs used to treat:

• Heart arrhythmias
• Malaria
• High cholesterol
• Bacterial infections
• Cancer

These are just a few types of medication that can make myasthenia gravis symptoms worse. Be sure any doctor prescribing you medication knows about your myasthenia gravis diagnosis. They can help choose options that are less likely to trigger symptoms. You may also want to check with your neurologist for added guidance.

Sometimes, a medication that might worsen MG is still the best option. In that case, you and your healthcare provider can weigh the pros and cons together. Make a plan with your neurology team before starting the medication, and know what steps to take if your symptoms get worse.

7. Treatment for Thyroid Disease

In people with both myasthenia gravis and an overactive thyroid, treating the thyroid condition can worsen MG symptoms. Researchers believe this may be due to how certain thyroid medications affect the immune system.

If you have both conditions, talk to your doctor before starting any treatment. They may proceed with extra caution or choose an option that’s less likely to worsen your MG symptoms. Your doctor can also help you create a plan in case your symptoms flare up.

8. Heat

Being too warm can cause symptoms of myasthenia gravis to worsen. High temperatures make it harder for the brain and muscles to communicate — and since MG already affects this process, heat can make symptoms feel more intense.

One MGteam member shared, “I’m trying to stay inside to beat the heat, which is not a friend anymore.”

Another shared, “I guess a hot shower takes me down the fatigue road.”

If heat makes your MG worse, take steps to stay cool, such as:

• Using your home’s air conditioning or fans to keep temperatures down
• Taking shorter or cooler showers
• Drinking iced beverages instead of hot ones
• Avoiding strenuous physical activity that can raise your body temperature

The key is to listen to your body and take action before overheating leads to a flare.

Talk With Others Who Understand

On MGteam, people share their experiences with myasthenia gravis, get advice, and find support from others who understand.

What triggers your symptoms — and what helps ease them? Let others know in the comments below.