A myasthenia gravis diagnosis can feel scary at first, but there’s good news. Most people living with myasthenia gravis can expect to have the same life expectancy as the general population. Your life expectancy is the average number of years you can expect to live.

Myasthenia gravis is a neuromuscular disease that affects how your nerves and muscles work together. It can cause flare-ups, when symptoms get worse, and times of remission, when symptoms improve. There’s no cure, but advances in the treatment of myasthenia gravis have gotten better and now help people live longer, healthier lives.

Although the life expectancy for people with myasthenia gravis is about the same as the general population’s, living with the condition may affect your risk for other health problems, such as thyroid diseases. Continue reading to learn more about how myasthenia gravis can affect your life expectancy.

Most people with myasthenia gravis have a normal life expectancy. In the United States, the average life expectancy is about 77.5 years, according to the Centers for Disease Control and Prevention (CDC). For females, it’s 80.2 years, and for males, it’s 74.8 years, according to the CDC.

The mortality rate (the rate at which people die) for people with myasthenia gravis may be highest within the first five years after diagnosis. Studies have found that certain factors may be associated with a lower life expectancy, such as:

• Being male
• Being diagnosed after the age of 50
• Having thymoma (cancer of the thymus gland)

Risk factors for a lower life expectancy with myasthenia gravis include being male, being diagnosed after age 50, and having cancer of the thymus gland.

Although most people with myasthenia gravis can expect a normal life expectancy, symptoms of myasthenia gravis can affect your quality of life, including your ability to complete daily tasks. Myasthenia gravis can also take a toll on your mental health. About 40 percent of people with the condition experience mood disorders. Living with symptoms, treatments, and changes to daily routines can lead to stress, anxiety, or depression.

What Are the Most Common Causes of Death for People With Myasthenia Gravis?

In the United States, the top two leading causes of death for the general population are heart disease and cancer. Researchers have found similar patterns in those with myasthenia gravis. A 2020 study in Sweden found that cancer and heart disease were the first and second most common causes of death among 4,000 people with myasthenia gravis. Myasthenia gravis itself was the third leading cause of death in this population.

The top two causes of death for people with myasthenia gravis are heart disease and cancer, followed by MG itself.

Myasthenia Gravis and Cancer

Cancer is a common cause of death for people with myasthenia gravis. People with the condition may have a higher risk of some types of cancer due to an association with thymoma and treatment with immunosuppressant medications.

Thymoma and Other Cancers

In the Swedish study, half of the people with both thymoma and myasthenia gravis died from cancer during the 10-year study period. This isn’t surprising, since people with thymoma-associated myasthenia gravis can also be at risk for other types of cancer.

A different study in the European Journal of Neurology found that, other than thymoma, the most common types of cancer in people with myasthenia gravis were:

• Skin cancer
• Cancer of the male genital organs
• Cancer of female genital organs
• Cancer of the digestive organs
• Breast cancer

A thymectomy is a procedure to remove the thymus gland. It may improve outcomes in some people with myasthenia gravis.

Talk to your neurologist about your risk for cancer. Your doctor may recommend cancer screening — testing for some cancers before you have any symptoms.

Immunosuppressants and Cancer

The use of immunosuppressant medications to treat myasthenia gravis has also been linked to an increased risk of some cancers.

Immunosuppressant medications can help treat myasthenia gravis because it’s an autoimmune condition. In autoimmune diseases, the body’s immune system makes antibodies (specialized immune system proteins) that mistakenly attack the neuromuscular junction, where your nerves and muscles connect. This attack blocks signals from reaching the muscles, leading to muscle weakness. It mostly affects the muscles you can control, called voluntary muscles or skeletal muscles.

Immunosuppressant medications can improve your symptoms of myasthenia gravis by stopping the immune system from making harmful antibodies. Examples of immunosuppressant medications used in myasthenia gravis include:

• Azathioprine (Azasan)
• Cyclophosphamide
• Cyclosporine (sold as Neoral, Sandimmune, and Gengraf)
• Eculizumab (Soliris)
• Mycophenolate mofetil (CellCept)
• Prednisone, a corticosteroid
• Rituximab (sold as Rituxan and other brand names)
• Tacrolimus (sold as Prograf, Astagraf XL, and Envarsus XR)

While immunosuppressants can help relieve myasthenia gravis symptoms, some of them can also make it harder for the immune system to find and fight new cancer cells. This might raise the risk of developing some types of cancer. Talk to your neurologist about the potential risks of your myasthenia gravis medication.

Myasthenia Gravis and Heart Disease

Lifestyle factors and medications related to myasthenia gravis may put people living with the condition at risk of developing heart disease or having a heart attack.

Muscle weakness and fatigue caused by myasthenia gravis can make physical activity and exercise more difficult. Lack of physical activity is one of the most important risk factors for heart disease.

Your risk of heart disease may also increase if you take corticosteroid medications like prednisone. Several of the potential side effects of prednisone are also risk factors for heart disease, such as:

• Weight gain
• Hypertension (high blood pressure)
• Diabetes
• Higher levels of cholesterol and triglycerides

Talk to your neurologist about your risk of heart disease and ways to prevent it.

Myasthenia Gravis-Related Death

Myasthenic crisis is a life-threatening complication of myasthenia gravis that can result in death from respiratory failure. A myasthenic crisis happens when your respiratory muscles (the muscles that help you breathe) become too weak to move air in and out of your lungs. During a myasthenic crisis, a person needs a ventilator to help them breathe.

Myasthenic crisis can be life-threatening, so it’s important to be aware of the early signs, such as:

• Increased muscle weakness
• Shortness of breath
• Difficulty swallowing

If you notice any of these symptoms, you should seek care immediately.

How Can You Improve Your Life Expectancy With Myasthenia Gravis?

For people with myasthenia gravis, steps for improving life expectancy are similar to those for the general population. The following tips may help you reduce your risk of cancer and heart disease:

• Eat a healthy diet rich in fruits and vegetables.
• Avoid foods high in saturated fat and trans fat.
• Avoid alcohol.
• Get at least 150 minutes of physical activity every week (about 30 minutes per day).
• Quit smoking.
• Protect your skin with high-factor sunscreen.

Developing healthy habits can also decrease your risk for other long-term conditions, such as diabetes and stroke.

The best ways to improve your life expectancy with myasthenia gravis are to stick to healthy habits and keep your MG well-controlled.

Managing Myasthenia Gravis

Take charge of your myasthenia care to manage your disease and prevent complications. Talk to your neurologist about the risks and benefits of myasthenia gravis treatment options, such as immunosuppressant medications, and how they may affect your risk of other medical conditions.

Make sure you and all of your healthcare providers know which drugs to avoid or use with caution during a myasthenic crisis, including:

• Antibiotics such as telithromycin, fluoroquinolones, macrolides, and aminoglycosides
• Beta-blockers
• Botulinum toxin (Botox)
• Corticosteroids in the initial phases of treatment
• Deferoxamine
• Hydroxychloroquine
• Magnesium
• Procainamide
• Statins
• Systemic lidocaine

Looking Ahead

If you’re living with myasthenia gravis, understanding your treatment options and how the condition may affect different parts of your life can help you feel more in control. Staying informed and working closely with your healthcare team are key steps toward managing the condition with confidence.

Talk With Others Who Understand

On MGteam, the social network for people living with myasthenia gravis and their loved ones, more than 3,000 members come together to ask questions, give advice, and share their stories with others who understand life with myasthenia gravis.

Are you living with myasthenia gravis? What steps have you taken to increase your life expectancy? Share your experience in the comments below, or start a conversation by posting on your Activities page.