Learning Your MG Triggers

Reviewed by: HU Medical Review Board | Last reviewed: October 2024 | Last updated: October 2024

Myasthenia gravis (MG) is a chronic autoimmune disorder that affects the communication between your nerves and muscles. This leads to muscle weakness that can worsen with activity and improve with rest. MG can affect muscles all over your body, including those responsible for breathing, swallowing, and moving your eyes, arms, and legs.1-3

Most people with MG find that they have times when their condition flares or gets worse. This is followed by times when the symptoms improve or go away completely. It is important to be aware of the things that can make your MG symptoms worse (triggers) and how to manage them. Figuring out what triggers your MG can help you manage it.2,4,5

What is an MG trigger?

A trigger can be anything that makes your MG symptoms, like muscle weakness or fatigue, worse. Triggers can be something in your environment, something you eat or drink, or how you feel emotionally.1,4,5

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Signs that your MG is getting worse may include:1-3

  • Trouble swallowing or speaking
  • Trouble breathing or shortness of breath
  • Trouble walking or holding onto things
  • Droopy eyelids or double vision
  • Feeling extremely tired

Common MG triggers

Some triggers are common to most people with myasthenia gravis, while others differ between people. Some of the most common MG triggers are:2,4,5

  • Not getting enough sleep
  • Physical and emotional stress
  • Infections, especially respiratory infections
  • Certain medicines, including beta-blockers, calcium channel blockers, and some antibiotics
  • Extreme temperatures (either hot or cold) and humidity
  • Bright light or sunlight
  • Hot foods or drinks

Other things can bring on MG symptoms in some people, too, like:1,4,5

  • Pregnancy
  • Menstrual periods
  • Low potassium levels
  • Low thyroid levels
  • Alcohol
  • Chemicals that are in household cleaners, bug sprays, and pesticides
  • Quinine or tonic water

How to learn what triggers your MG

Myasthenia gravis can be a highly unique condition. Everyone’s triggers may be different, and they may change over time. For example, some people need extra sleep to stay healthy, while others must avoid hot coffee.3

A symptom diary is the best way to figure out what triggers your muscle weakness and whether those triggers are changing over time. A symptom diary can include a daily record of:5

  • Your symptoms by time of day
  • What you were doing before the symptoms flared
  • Whether you took any drugs or did anything else, like resting, to treat your symptoms
  • Whether treatment made the weakness better, and how quickly it worked

You should also record when you feel at your best and worst each day. After some time, you may notice patterns in your triggers and what treatment options work best for you. Once you know your triggers, you can take steps to avoid them.4,5

You also may want to keep track of how much exercise you get and what types, and what you eat and drink. This information may give you clues for things in your lifestyle that may help or aggravate your MG symptoms.

The Myasthenia Gravis Foundation of America offers a free app, myMG, that many people use to track their symptoms. And there are several other healthy diary apps available for free or at low cost that you can use to track your condition, your medicines, and more.