Briefly about Myasthenia Gravis

Myasthenia gravis is an autoimmune disease that can affect both women and men. Symptoms typically appear in adulthood, but in very rare cases, children and adolescents can develop myasthenia gravis. The disease is not hereditary.

It affects the muscles, which become easily fatigued. Symptoms vary from person to person, but the first signs are often drooping eyelids, double vision, or crossed eyes. Many will later also experience weakness in the arms and legs and/or difficulties with chewing, swallowing, or speaking.

It is possible to treat myasthenia gravis with medication, but most people will still experience some symptoms.

An Autoimmune Disease

Myasthenia is an autoimmune disease. This means that the immune system attacks the body’s own tissue by producing antibodies.

In myasthenia, antibodies are produced that target the areas on the muscle cell that receive signals from the nerve cell to contract. These areas are called receptors, and the nerve cells communicate with them using the protein acetylcholine. The antibodies are thus directed against the acetylcholine receptors on the muscle cell. (In rare cases, other types of receptors may be involved)

The antibodies block the muscle receptors, preventing acetylcholine from signaling to the muscle. When enough of the receptors are blocked, it results in impaired muscle function, which manifests as reduced endurance and decreased muscle strength.

In principle, all muscle groups can be affected, but for many people, the first symptoms often include drooping eyelids, double vision, slurred speech, difficulty smiling, falling down or dropping things.

Not a Hereditary Disease

The cause or exact mechanism behind the disease is unknown. It is known to be due to changes in the immune system, and it is not hereditary.

Who Can Get Myasthenia Gravis?

Both women and men can develop the disease. Most people are diagnosed in adulthood, but in very rare cases, the disease can occur in children and adolescents.

Among those diagnosed between the ages of 15 and 40, the majority are women. However, if the disease first appears after the age of 55, it is more common in men than in women.

There are approximately 5 new cases pr 1 million people each year.

The Course of Myasthenia Gravis

There is significant variation from person to person in terms of which symptoms appear first and how the disease progresses. This can make diagnosing myasthenia gravis difficult, and the condition can sometimes be mistaken for other diseases.

In principle, all voluntary muscle groups can be affected, but the eye muscles are often the first to show symptoms. Up to 85% of people experience double vision and/or drooping eyelids as the initial signs. Many will later develop symptoms in the arms, hands or legs and/or have difficulties with chewing, swallowing, or speaking.

In most cases, the disease is chronic, but around 5% of patients become completely symptom-free following medical treatment.

Common Symptoms

Symptoms of myasthenia typically involve fluctuating muscle fatigue—physical tiredness and weakness that worsens with sustained use of the affected muscles. This fatigue can appear suddenly and result in a range of symptoms depending on which muscles are involved. Typical examples include:

  • Drooping eyelids, double vision, or misalignment of the eyes
  • Slurred or unclear speech, mild difficulty swallowing
  • Difficulty lifting the head while lying down
  • Fatigue in the arms when held up against gravity
  • Legs feeling very tired during walking or stair climbing
  • Fatigue may also occur without prior physical activity

Myasthenia itself does not cause pain, sensory disturbances, or similar issues. However, muscle pain from compensatory movements is often reported.

When Does Fatigue Occur?

It is characteristic that fatigue or weakness appears after repeated use of the muscles and improves after a period of rest. Symptoms often vary throughout the day and are typically most pronounced in the evening.

Experience shows that symptoms may worsen during periods of high stress and/or significant physical, mental, or social strain.

Fatigue Is Common

Many people with myasthenia experience significant fatigue. It can occur after physical exertion, but it may also be present from the moment they wake up. This fatigue can be highly limiting, preventing participation in activities or affecting the ability to work.

If the Breathing Muscles Are Affected, It Can Be Serious

In very rare or untreated cases, myasthenia can lead to fatigue of the respiratory muscles, resulting in reduced coughing strength and labored breathing, which may develop into a life-threatening condition. This typically occurs in connection with the flu or an infection. If breathing problems arise, immediate medical attention is required.

Lack of Facial Expression and Slurred Speech Can Lead to Misunderstandings

A lack of facial expression or unclear speech may cause misunderstandings or inappropriate assistance from others. It is therefore important for people with myasthenia to carry an information card with their diagnosis or ensure that their relatives can inform others about the condition.

Treatment and Support

Treatment for myasthenia gravis typically involves medication, and for some, physical exercise can also be beneficial. You can read more in our insights on medical treatment for myasthenia gravis and physical therapy with myasthenia gravis.

Psychological Support

For most people with myasthenia, their disability is not immediately visible, which can make it difficult for others to understand their struggles. Uncertainty about the future can also be mentally exhausting. Speaking with a psychologist can help relieve anxiety and uncertainty.