Myasthenia gravis life expectancy
Last updated Jan. 27, 2025, by Lindsey Shapiro, PhD
Fact-checked by Joana Carvalho, PhD
While there is no cure for myasthenia gravis (MG), the rare neuromuscular disease generally has a good prognosis, with most patients having an average life expectancy. Advances in MG diagnosis and care have made deaths directly related to MG uncommon. However, in severe cases, the disease can still have life-threatening consequences.
MG is an autoimmune condition driven by self-reactive antibodies that attack proteins important for nerve-muscle communication, leading to symptoms of weakness and fatigue that can affect muscles throughout the body. Disease progression is highly variable, being mild for some people and severe for others.
A variety of factors, including MG type, respiratory involvement, and tumors in the thymus gland can influence MG life expectancy. There’s no way to specifically predict how long a person will live with MG, but proper treatment and a healthy lifestyle can help patients live full and active lives.
What are the factors affecting MG life expectancy?
The incidence of MG in the U.S. and globally — including in Africa, Asia, and Europe — has been increasing in recent years, which has been attributed in part to improved diagnosis and care that enable patients to live longer.
Early death used to occur in around a third of people with MG, but this has become increasingly rare with improvements in management and care. Now, MG life expectancy is around what would be expected in the general population for most patients. Currently, it’s estimated that fewer than 10% of MG patients die from the disease. Other than MG itself, studies have found that leading causes of death among people with the condition include heart disease and cancer — the same as in the general population.
While the prognosis for MG is generally good, there are a few factors that can increase the likelihood a person has of experiencing more severe consequences from the disease. Factors that may influence life expectancy in MG include:
- disease type
- myasthenic crisis, a severe MG complication that can cause respiratory failure
- the presence of a thymoma, a type of tumor in the thymus gland
- older age
- male sex.
MG type
MG prognosis is generally good across all three main forms of the disease — ocular MG, generalized MG (gMG), and transient neonatal MG — although disease type can influence the likelihood that a person will experience potential life-threatening complications.
For people with ocular MG, weakness is confined to the muscles that control eye and eyelid movements. Ocular MG life expectancy is generally normal.
In gMG, muscle weakness is more widespread and can affect any part of the body, which can increase the odds of certain life-threatening complications, including:
- myasthenic crisis, which is associated with weakness in the muscles that are needed for breathing
- choking or aspiration pneumonia, a lung infection that occurs when food or liquids are accidentally inhaled into the airways, both of which are associated with weakness in bulbar muscles, or those in the head and neck.
Despite these possible complications, gMG and bulbar MG life expectancy generally remains good with proper management.
Transient neonatal MG is a rare type of the disease where babies born to a mother with MG also develop the condition. MG symptoms usually disappear in the weeks or months following birth without long-lasting consequences and life expectancy is not generally affected.
Myasthenic crisis and respiratory involvement
A serious complication of MG — and a factor most likely to influence life expectancy — is a myasthenic crisis, a medical emergency where weakness in respiratory muscles causes severe breathing problems that require hospitalization. Around 15%-20% of MG patients experience at least one myasthenic crisis in their lifetime.
Historically, deaths from myasthenic crises were much more common, occurring in around 50%-80% of patients who experienced them, but improvements in MG treatment and management strategies, including ventilation assistance (e.g., oxygen masks, breathing tubes), intravenous immunoglobulin, and plasmapheresis, have substantially reduced mortality rates. Nowadays, it’s estimated that fewer than 10% of people who experience a myasthenic crisis die from it.
Myasthenic crises can be triggered by a number of factors, including stress, pregnancy, and certain medications, but respiratory infections are the most common. Studies show that respiratory infections, such as flu or pneumonia, are commonly linked to myasthenic crisis and are associated with an increased risk of death in MG patients. Several other studies have also associated respiratory illnesses with death in MG.
Thymoma
Thymomas are tumors that develop in the thymus gland, a small organ in the chest that plays a key role in the immune system. These tumors are found in about 10%-15% of MG patients and are thought to contribute to the development of the disease.
A number of studies have identified thymoma as a factor associated with worse survival in MG. Moreover, some studies have found that among all people treated for a thymoma, survival is lower among those who also have MG.
Other factors
Several studies have found that an older age at diagnosis is associated with a worse MG prognosis, with survival rates generally being lower for people older than 50. Juvenile MG, a form of the disease where symptoms appear during childhood or adolescence, is generally associated with a better prognosis than adult-onset MG. Juvenile MG life expectancy is usually normal.
Some studies have also found that, even though MG is more prevalent in women, male patients may be at a slightly higher mortality risk than female patients.
Can treatment increase MG life expectancy?
While there is no cure for MG, there are several treatments available to help keep symptoms at bay and enable patients to live an active and healthy life. For some, this could lead to a temporary or permanent state of remission, where the disease is kept under control and patients have minimal or no symptoms.
Every patient responds to treatment differently, but it’s possible that appropriate treatment and monitoring can help to improve life expectancy for MG patients by keeping symptoms under control and reducing the likelihood of life-threatening complications such as myasthenic crisis. Proper disease management may also help slow or delay the progression of ocular MG to gMG.
MG life expectancy with treatment is generally similar to the average seen in healthy people. Specific treatments that have been associated with a positive impact on survival in MG patients include:
- thymectomy, or surgery to remove the thymus gland
- immunosuppressant medications.
Some MG patients have refractory, or treatment-resistant, disease and fail to respond to available treatments. These patients may be at a higher risk of experiencing life-threatening complications and death than those who do respond to treatment.
Ultimately, every patient is different, and treatment choices are influenced by a number of different factors. There’s no guarantee that a treatment will extend a person’s life expectancy.
Future outlook and lifestyle changes
While many people live full and active lives with MG, the disease can substantially impact a person’s quality of life and emotional well-being. It’s important to work closely with a healthcare team to develop a tailored treatment plan that reduces the chances of life-threatening complications and makes living with MG as manageable as possible.
Making certain lifestyle changes after an MG diagnosis may help patients maximize their physical health and improve their quality of life. Many of these changes are similar to those recommended for the general population to improve mental health and lower the risk of cancer, heart disease, and other health problems. While there is no guarantee that lifestyle changes will extend a person’s life expectancy, when combined with appropriate MG treatments, they can help patients live as healthily as possible. Some lifestyle changes that may be beneficial include:
- eating a healthy diet
- drinking less alcohol and quitting smoking
- managing stress
- staying active and following an appropriate exercise regimen.
It’s important to note that every patient’s needs are different. Individuals should always consult their doctor before making any lifestyle changes to ensure they are safe and suitable for their specific situation.
Myasthenia Gravis News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.
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