Taking control: Managing MG relapses

Last updated Jan. 2, 2025, by Marisa Wexler, MS
Fact-checked by Joana Carvalho, PhD

Myasthenia gravis (MG) is a chronic neuromuscular disorder that’s characterized by muscle weakness and fatigue. For most people with the disease, MG is marked by periods of remission alternating with periods of relapses.

An MG relapse is a period of time where disease symptoms reappear or suddenly worsen in the form of a flare or exacerbation after a period of MG remission, which is when symptoms are usually mild or completely absent.

MG relapses can be disabling or even life-threatening in the most severe cases. Though with the use of available medical treatment, it’s fairly uncommon for MG relapses to be fatal.

A variety of prevention strategies can help reduce the risk of relapses, and treatments can help manage these episodes when they do occur.

Identifying a relapse

In general, potential signs that can help you identify an MG relapse include:

• worsening of existing symptoms
• appearance of new symptoms
• lack of response to medications that were previously effective keeping symptoms under control
• increased need for higher treatment dosages to achieve the same level of symptom relief.

What does an MG relapse feel like?

MG symptoms can vary from person to person and even for the same individual over time. This also applies to relapses: The experience of an MG relapse for one person may be very different from that of another person with the disease.

An MG relapse can seem like any MG symptom that suddenly worsens. It often causes existing symptoms of muscle weakness and fatigue to become more intense and/or new ones to arise.

MG relapse symptoms may affect different parts of the body, also depending on which specific muscle groups were originally impacted by MG. For instance, during relapses, people with ocular MG may experience symptoms related to increased weakness in the muscles that control eye and eyelid movements, such as blurry or double vision or eyelid droopiness.

In the case of people with generalized MG, symptoms during a relapse may impact a wide variety of muscles, including those in the face and neck (bulbar muscles), arms and legs (limb muscles), as well as those required for breathing (respiratory muscles). Relapse symptoms in people with generalized MG may include:

• changes in facial expression
• difficulty speaking
• problems chewing and swallowing
• difficulty moving the arms and grabbing things
• difficulty walking
• difficulty holding the head upright
• shortness of breath.

MG relapse vs. myasthenic crisis

A myasthenic crisis is the most severe MG manifestation that can happen during a relapse.

The defining feature of a myasthenic crisis is weakness in respiratory muscles, which makes it hard for a person to breathe. This is an emergency that requires immediate medical care.

Around 1 in 5 people with MG will experience a myasthenic crisis at some point over the course of their illness. MG crises can be life-threatening and as many as 80% of these events used to be fatal. Available treatments have dramatically improved the outcomes of a myasthenic crisis, however, and nowadays rates of mortality associated with it are less than 5%.

Causes and triggers

While it’s not always clear what causes MG relapses, there are triggers that are more likely to increase a person’s risk of experiencing a disease relapse. Examples of such MG triggers include:

• not getting enough sleep
• stress, anxiety, depression, or other emotional issues
• temperatures that are very hot or very cold
• humidity
• physical stress or injury
• overexertion, particularly with repetitive movements
• illness or infection
• surgery
• consuming alcoholic beverages, quinine, or tonic water
• certain medications, including some antibiotics, blood pressure medicines, and anesthetic agents
• low levels of potassium or thyroid hormones
• exposure to certain chemicals, including some pesticides and cleaning agents
• hormonal changes associated with menstrual periods and pregnancy.

Managing MG relapses

Often, the first step in treating an MG relapse is to identify and eliminate any potential triggering risk factors. For example, if you are taking a medicine that’s known as a potential trigger, discontinuing that medicine may help with managing the relapse.

When a relapse occurs, there are several MG treatment options that can get the disease under control. Exactly which types of treatments are used will depend upon the severity of the relapse.

Mild relapses may not require any medical intervention and symptoms may be brought under control by adjusting medications or resting. A severe myasthenic crisis usually requires hospitalization and emergency treatment.

When treatment is necessary, it usually involves medicines to suppress the immune system, including immunosuppressants and corticosteroids, and/or medications to help boost muscle strength, such as anticholinesterases. If a myasthenic crisis impairs breathing, invasive ventilation may also be necessary to ensure you are able to breathe properly.

Rescue treatments, such as intravenous immunoglobulin therapy and plasmapheresis, may also be used for more severe symptoms or in emergency situations, including myasthenic crisis.

Long-term strategy and prevention

It isn’t always possible to completely prevent MG relapses, but there are steps that can be taken to minimize the risks, including avoiding potential triggers. Some of these include:

• getting enough sleep
• having good hygiene practices, such as washing hands, to reduce the risk of infections
• avoiding alcohol and toxic chemicals
• using strategies such as mindfulness or meditation to deal with stress
•  avoiding overexertion when being physically active
• communicating clearly with healthcare professionals so that they know to avoid using medicines that may act as MG triggers
• taking prescribed MG therapies as instructed by a healthcare professional
• having regular medical follow-ups.

In addition to taking steps to avoid potential triggers and following the prescribed treatment plan, there are long-term therapeutic options that may be considered to reduce the risk of MG relapses. These can include thymectomy, which is the surgical removal of the thymus gland, as well as long-term treatment with certain immune-suppressing therapies.

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.