Learning Your MG Triggers

Reviewed by: HU Medical Review Board | Last reviewed: March 2021

One of the traits myasthenia gravis (MG) shares with other chronic autoimmune conditions like multiple sclerosis and lupus is that certain things can trigger flares. Figuring out what triggers your MG is an important way to help manage your disease.1-3

What is an MG trigger?

Most people with MG find that they have times when their disease flares or gets worse. This is followed by times when the symptoms improve or go away completely.

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

Signs that your MG is getting worse include:2

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

Common MG triggers

Some triggers are common to most people with myasthenia gravis, while others are unique to the person. Some of the best-known MG triggers are:1,2

  • Overdoing it or not getting enough sleep
  • Infections, especially respiratory infections
  • Certain drugs, 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
  • Surgery
  • Pregnancy
  • Menstrual periods
  • Magnesium
  • Alcohol drinks
  • Some household cleaners, bug sprays, and pesticides
  • Quinine or tonic water
  • Physical and emotional stress

Infections and illness can increase muscle weakness for long after the illness has passed. To avoid as many infections as possible, doctors often recommend people with MG get an annual flu shot and stay current on all other vaccines.

Surgery can be especially hard on a person with MG since it stresses the body and anesthesia is complicated for people with MG. You should talk to your MG doctor if you have any upcoming surgeries about pre-surgery strategies to prevent an MG flare after surgery.3

Tracking your symptoms

Like everything else with myasthenia gravis, everyone’s triggers are different and may change over time. Some people need extra sleep to stay healthy, while others must avoid hot coffee.

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 should include a daily record of:3

  • Your symptoms by time of day
  • What you were doing before the symptoms flared
  • If you took any drugs, or did anything else like rest, 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 will begin to notice patterns to your triggers and what treatment options work best for you. Once you know your triggers you can take steps to avoid them.

You may also 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 disease. There are several other healthy diary apps available for free or at low cost that you can use to track your disease, your medicines, and more.

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