Disorders

What is myasthenia gravis?

Reviewed June 2026 by Jennifer Martinez-Thompson, MD, FAAN

Definition: Myasthenia gravis is a rare condition that causes muscle weakness. It happens when the immune system disrupts the signals that nerves use to tell muscles to move. This can make everyday activities (like seeing clearly, speaking, swallowing, walking, or breathing) more difficult.  

With the right diagnosis and treatment plan, many people can manage their symptoms and continue daily activities with more confidence.

Myasthenia gravis is uncommon. Worldwide, it affects about 20 out of every 100,000 people. It can affect people at different ages, but it’s more common in women before age 40 and men after age 60.

What are the symptoms of myasthenia gravis?

Symptoms are caused when muscles tire more easily than usual due to disrupted nerve signals. They may come and go, worsen with activity, and improve with rest. Symptoms can affect different parts of the body.

Common symptoms include:

  • Drooping eyelids
  • Double vision
  • Trouble speaking clearly
  • Difficulty chewing or swallowing
  • Weak muscles in the arms, legs, or neck
  • Breathing problems, in severe cases

What are the causes and risk factors of myasthenia gravis?

Myasthenia gravis affects the way nerves and muscles communicate. In most cases, the immune system makes antibodies (proteins that usually help you fight germs) that mistakenly disrupt the signals muscles need to move.

You may be more at risk for myasthenia gravis if you have other autoimmune conditions, an enlarged thymus gland, or a tumor affecting the thymus gland (thymoma). Myasthenia gravis usually doesn’t run in families.

How is myasthenia gravis diagnosed?

A clinician may use several tests to diagnose myasthenia gravis and understand which muscles are affected. These may include:

  • A neurological exam to check reflexes, muscle strength, balance, and vision
  • Blood tests to detect abnormal antibodies
  • Nerve stimulation tests to assess muscle fatigue
  • Imaging tests such as CT or MRI to examine the thymus gland

What treatments are available for myasthenia gravis?

Treatment can help improve symptoms, reduce flare-ups, and support daily life. The right approach depends on your symptoms, age, overall health, and the type of antibodies you have.

Medications

  • Anticholinesterase inhibitor medicines help nerves and muscles work better together
  • Steroids and other immune treatments lower the body’s harmful immune response

Advanced treatments

  • Complement inhibitors (eculizumab, ravalizumab, zilucoplan) or FcRn inhibitors (efgartigimod, rozanolixizumab, nipocalimab) may be used for moderate to severe cases caused by certain antibodies that don’t improve with first-line treatments
  • Rituximab may also help some people who don’t respond to other treatments

Other treatments

  • IVIG (intravenous immunoglobulin) or plasma exchange (PLEX) can be used as rescue therapy for disease exacerbations or crisis, or for people who don’t respond to other treatments
  • Thymectomy (surgery to remove the thymus) may be considered for some people with acetylcholine receptor antibodies

Caring for and navigating myasthenia gravis

Explore practical tips, personal stories, and expert guidance for living well with myasthenia gravis.

Frequently asked questions

Is myasthenia gravis genetic or inherited?

Myasthenia gravis is not considered an inherited disease.The condition is usually linked to antibodies that affect the signals between nerves and muscles.

In rare cases, a baby may have temporary symptoms if the mother has myasthenia gravis. This is called neonatal myasthenia gravis and usually improves with medical care.

What triggers myasthenia gravis symptoms or flare-ups?

Symptoms can flare or feel worse during times when the body is under extra stress. Common triggers include:

  • Some medicines (such as certain antibiotics or heart medicines)
  • Illness or stress on the body, including pregnancy
Does myasthenia gravis affect daily life and is it life-threatening?

Myasthenia gravis can affect daily life by making tasks harder when muscles feel weak or tired. In some cases, it can affect breathing and require urgent care. With treatment and monitoring, many people are able to manage their symptoms and live full, active lives.

What is a myasthenic crisis?

A myasthenic crisis is a medical emergency. It happens when the muscles used for breathing become too weak, which can lead to respiratory failure. Anyone with symptoms such as severe shortness of breath, trouble swallowing, or sudden worsening weakness should seek emergency care right away.

Myasthenia gravis resources

Find organizations that provide helpful information for people living with myasthenia gravis and their families.