The Outlook for Someone With Myasthenia Gravis
Reviewed by: HU Medical Review Board | Last reviewed: May 2021 | Last updated: April 2023
Myasthenia gravis (MG) is a disease that causes certain muscles to become weak. The muscles involved are called voluntary muscles, or the ones a person can control.
Normally, when you think about moving a muscle, the movement is triggered by an electrical pulse from a nerve that travels to a muscle. With MG, the body begins to attack healthy spots on the muscle that receive signals from nerves. This causes the muscles to become weak and tire easily.1-3
The snowflake condition
Myasthenia gravis (MG) is often called a snowflake disease because it can be so different from person to person. One person may have constant, mild weakness in the eye muscles while another has occasional, severe weakness in the neck and shoulder muscles. Some find that current MG drugs work well to control their symptoms while others struggle to find a treatment that works.
MG is a chronic autoimmune condition. Chronic means long-term, and autoimmune means that the body’s immune system attacks healthy tissue. The muscles most often involved in MG include muscles that control:1-3
- Arm and leg movement
- Eye movement and eyelids
- Speech, chewing, and swallowing
However, not all of these muscles are affected the same way, or at the same time, even in one person. Different muscles may be impacted from 1 minute, hour, day, or year to the next.
Generally, weakness goes from mild to severe over weeks or months, with flares and remission in between. While every case of MG can be different, doctors have identified some common trends, including:4-6
- 4 out of 10 people with MG begin with eye problems like double vision or droopy eyelids
- Only 15 percent of people have only eye muscle weakness 2 years after symptoms begin
- Muscle weakness usually peaks within the first 3 years
- After the first 3 years, most people with MG become stable or improve
- People with MG and a second autoimmune condition tend to have more severe MG
- People with just 1 eye symptom tend to get worse more quickly than people with both double vision and droopy eyelids
- People with ocular MG (weak eye muscles only) and an enlarged thymus tend to get worse more quickly than people with other thymus issues
- 15 percent of people with MG have refractory MG, or MG that does not respond to treatment
- Thymectomy improves symptoms in most people and some even go into remission after surgery
People with untreated myasthenia gravis are at higher risk of developing breathing problems, choking, pneumonia, and falls.4
Up to 4 out of 10 people with MG go into remission, which means their muscle weakness disappears completely. Remission is usually temporary and may come with occasional flares, but it is permanent in some people. During remission, some people can stop taking all of their MG drugs.5
Between 4 and 6 out of 10 people who have a thymectomy achieve remission. Thymectomy is a surgery to remove the thymus gland. The chances of remission increase for 7 to 10 years after the surgery.4
Can myasthenia gravis be cured?
There is no cure for MG, but most people with the condition have a normal life span. Only 3 to 4 out of every 100 people with MG die because of MG. Years ago, early death occurred in over a third of people with MG. Today, if someone dies of MG, death is usually due to a myasthenic crisis or a thymoma.4
Treatments can help control many of the symptoms and let people live a normal or near-normal life. However, MG is so different between people that some struggle to return to their pre-MG health while others go into remission for a time.1