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Myasthenic Crisis


  • Myasthenic crisis (MC) is a life-threatening condition where the muscles you use for breathing become very weak. Myasthenic crisis is also called myasthenic gravis crisis. Weakened breathing muscles may cause severe breathing problems and lead to lung failure. MC is the worst form of myasthenia gravis (MG). In MC, the muscles used during breathing and swallowing are weak and do not function properly. When this happens, you may have trouble breathing. You may need a breathing machine to help you breathe and live.
  • Anything that may worsen MG may trigger or lead to MC. Your risk for MC increases with a lung infection, fever, or being stressed. Certain medicines, such as antibiotics, heart medicines, steroids, and anticholinesterase inhibitors may also trigger MC. You may have shortness of breath, difficulty swallowing or talking, and morning headaches. Imaging tests, blood tests, and pulmonary function tests may be needed. Treatment for MC includes endotracheal (ET) tube placement, IV fluids, and removing factors that may trigger your MC. Immune globulins, steroids, and anticholinesterase inhibitors may also be given. Plasma exchange to remove the antibodies (body substances) in your blood causing MC may also be needed.
  • MC is an emergency condition, and you may die if it is not treated right away. Treating MC may make your muscles stronger so you can breathe better. Treatment may prevent your lungs from failing.


Take your medicine as directed:

Call your primary healthcare provider if you think your medicine is not helping or if you have side effects. Tell him if you are allergic to any medicine. Keep a list of the medicines, vitamins, and herbs you take. Include the amounts, and when and why you take them. Bring the list or the pill bottles to follow-up visits. Carry your medicine list with you in case of an emergency.

    • Anticholinesterase medicine: Anticholinesterase is medicine that increases the amount of acetylcholine in your muscles. Acetylcholine is a special body chemical that helps your muscles and nerves communicate (talk to each other) better. It helps you get stronger. You may also take this medicine with steroids. Do not stop taking these medicines without your caregivers OK.
    • Immune globulins: This medicine is given as a shot or an IV infusion to make your immune system stronger. You may need immune globulins to treat or prevent an infection. It is also used when you have a chronic condition, such as lupus or arthritis. You may need many weeks of treatment. Each infusion can take from 2 to 5 hours.
    • Immunosuppressive therapy: These medicines may be given to decrease muscle weakness and slow down your immune system. The immune system protects your body from infections and diseases. The immune system may see normal cells as abnormal. These medicines may prevent your immune system from causing symptoms of MC. Do not stop taking these medicines without your caregivers OK. Stopping on your own can cause problems.
    • Supplements: Certain medicines used to treat MC may cause your bones to weaken. Your caregiver may give you vitamin D and calcium to help prevent bone loss and fractures. Ask your caregiver for more information about these supplements.

Ask for information about where and when to go for follow-up visits:

For continuing care, treatments, or home services, ask for more information.

Breathing exercises:

  • Diaphragmatic breathing: Diaphragmatic breathing can help strengthen some of the muscles you use to breathe.
    • 1. Place one hand on your stomach just below your ribs. Place your other hand in the middle of your chest over your breastbone.
    • 2. Breathe in slowly through your nose, as deeply as you can.
    • 3. Breathe out slowly through pursed lips. As you do so, tighten the muscles in your stomach. Use your hand to gently push in and up while tightening the muscles.
    • 4. Diaphragmatic breathing takes practice. You may need to practice this many times a day. Slowly increase the amount of time you spend during each practice session.
  • Pursed-lip breathing: Pursed-lip breathing can be used any time you feel short of breath. Pursed-lip breathing can be especially helpful before you start an activity.
    • 1. Inhale (breathe in) through your nose. Be sure you are using the muscles in your abdomen to help fill your lungs with air.
    • 2. Slowly exhale (breathe out) through your mouth with your lips pursed (slightly puckered). An example of pursed lips is when you pucker your lips to blow out a candle. You should make a quiet hissing sound as you breathe out through your pursed lips.
    • 3. Try to take as long as you can to breathe out. It should take you twice as long to breathe out as it did to breathe in. This helps you get rid of as much "used" air from your lungs as possible.
    • 4. Repeat this exercise several times. Once you are used to doing pursed-lip breathing, you can do it any time you need more air.

Breathing treatments:

You may need breathing treatments to help open your airways so you can breathe easier. A machine may be used to help you breathe in medicine. A caregiver will show you how to do these treatments. At first you may need them more often. As you get better, you may only need the treatments when you are having trouble breathing.

Manage your stress:

Stress may slow healing and lead to illness. Learn ways to control stress, such as relaxation, deep breathing, and music. Talk to someone about things that upset you.


  • You have loose bowel movements, feel like throwing up, or have stomach upset after taking your medicine.
  • You have a fever, cough, or a cold.
  • You have morning headaches.
  • You miss taking any of your medicines used to treat your MG.
  • You have questions about your condition, medicine, or care.


  • You suddenly have trouble breathing or swallowing.
  • You suddenly have trouble talking.
  • Your symptoms of muscle weakness worsen even after taking your medicines.

The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

Learn more about Myasthenic Crisis (Aftercare Instructions)

Associated drugs

IBM Watson Micromedex

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.