8 Signs and Symptoms of Myasthenia Gravis
Key takeaways:
Myasthenia gravis is an autoimmune disease. People with myasthenia gravis develop muscle weakness that gets worse with activity and improves with rest.
Common symptoms of myasthenia gravis include double vision, eyelid drooping, facial weakness, and sometimes breathing difficulty.
Myasthenia gravis can flare up due to infection, stress, certain medications, or anesthesia for surgery.
Table of contents
Myasthenia gravis is an autoimmune condition. People with myasthenia gravis develop antibodies that attack and destroy receptors on the surface of muscle cells. These receptors allow nerves to communicate with muscles, telling them when it’s time to move.
Over time, as more receptors get damaged, people develop weakness throughout their body. Early myasthenia gravis symptoms can be very subtle. They then worsen slowly over time. Also, symptoms get worse over the course of the day but then get better after people rest their muscles during sleep.
Often, people might not realize early symptoms are a sign of an autoimmune disease. They end up pinning these symptoms on things like being tired, poor sleep, or illness. That’s because early symptoms can get better for short periods of time.
Myasthenia gravis is just one type of autoimmune disease. Learn about causes, types, and diagnosis for other autoimmune diseases.
Droopy eyelids and facial muscle weakness: These could also be symptoms of Bell’s palsy. But this condition affects only one side of the face and comes on suddenly.
How does myasthenia gravis feel? One person describes her decades of experience with this condition.
As a result, people don’t seek help until symptoms get worse. By then, the antibodies have damaged more receptors. Picking up on early symptoms allows people to start treatment sooner, when myasthenia gravis is easier to treat.
Here are some symptoms of myasthenia gravis you don’t want to miss.
1. Vision changes
The most common early sign of myasthenia gravis is changes to your vision. You might notice symptoms like:
Blurry vision: Early on, the imbalance between the eye muscles may be slight, and people may experience this change as blurry vision. Over time, the blurry vision will turn into double vision.
Double vision: Double vision develops because some of the eye muscles weaken faster than others. This leads to an imbalance in the force the muscles put on the eyeball. The muscles with more healthy receptors pull harder on the eyeball, causing eye malalignment and double vision.
The eyeball movement is controlled by several small muscles. Small muscles are more likely to develop weakness earlier than large muscles in people with myasthenia gravis. That’s because smaller muscles have fewer receptors on their surfaces to accept signals from nerve cells. So, damage to even a few receptors on these small muscles leads to symptoms.
These vision changes develop slowly, over weeks or months. Once they’ve arrived, they get worse over the course of the day as you use your eyes. Vision changes tend to get better or disappear by morning because your eyes haven’t moved much overnight.
2. Droopy eyelids
Eyelid weakness is another common early symptom of myasthenia gravis. The muscles that open the eyelid are very small, making them more susceptible to weakness from receptor damage. These are classic signs of early myasthenia gravis:
One or both of your eyelids don’t open as much as they used to.
Eyelid weakness gets worse throughout the day.
Your eyelids seem higher when you wake up in the morning.
These symptoms may change from day to day. One day, your right eyelid may droop lower. And the next, your left eyelid may droop more than your right. If you’re not sure whether your eyelids are drooping more, use a photograph of your face for comparison.
About half of all people with myasthenia gravis end up seeking medical attention because of droopy eyelids and/or double vision. Most people with vision problems go on to develop other symptoms from myasthenia gravis. But 10% to 15% of people have “ocular myasthenia gravis,” which is when the condition affects only the eyes.
3. Changes in your smile
The muscles in your face control your facial expressions. They let you smile, frown, and move your eyebrows. But these muscles are also very small, making them prone to weakness from receptor damage.
This is why smile changes are a common early symptom of myasthenia gravis. As the receptors of the mouth muscles get damaged, people have trouble lifting the corners of their mouth. When you try to smile, the middle of your upper lip may move. But the corners of your mouth won’t turn up.
This change in your smile may be subtle at first. Over time, though, it’ll become more noticeable. Other people may first point out changes in your smile. You can use an old photograph to compare whether your smile has changed.
4. Voice changes
Myasthenia gravis can affect the small muscles that lift the muscles in the back of your mouth, called your soft palate. Weakness in these muscles can lead to voice changes. People with myasthenia gravis may notice:
Changes in the sound of their voice, usually becoming more nasally than usual
Trouble raising their voice
Difficulty with changing pitch or tone
In the morning, after these muscles have had a chance to rest overnight, you may notice that your voice sounds more normal. But the voice changes should return and get worse throughout the day.
5. Trouble chewing
The small muscles around your jaw can also weaken because of myasthenia gravis. Early on, you might only notice that it’s taking you longer to chew food or that you quickly tire of chewing gum. Over time, this weakness can lead to more obvious symptoms like swallowing difficulties.
6. Speech problems
Facial muscle weakness is to blame here as well. You might notice:
Slurring words
Difficult pronunciation
Vocal fatigue, or your voice wearing out more easily with time
Similar to the other symptoms, speech problems tend to get worse as the day goes on.
7. Limb weakness
Weakness in the limbs usually affects both sides of the body in the muscles closer to your trunk, such as your hips and shoulders. So, this could cause difficulties with:
Getting up from a chair
Climbing stairs
Lifting your arms overhead
Keeping your head upright
But sometimes it affects distal muscles, too, like those in your wrists, feet, and ankles. This is less common. You might notice:
Shuffling gait
Tripping often
Weaker grip
8. Shortness of breath
Myasthenia gravis can affect muscles that help you breathe, in your chest and those around your airway in your throat. This weakness can cause someone to feel short of breath or more easily winded with activity. When weakness is severe, it can lead to urgent respiratory problems.
When should you see a healthcare professional about myasthenia gravis symptoms?
Seek medical attention right away if you notice sudden vision changes, muscle weakness, or trouble breathing.
Remember, myasthenia gravis symptoms start off slowly. Sudden vision changes or facial weakness can be a sign of life-threatening conditions, like stroke.
If your symptoms have been slowly getting worse over time, see a healthcare professional or eye doctor as soon as possible. Your symptoms may not be from myasthenia gravis. But it’s important to get checked as soon as possible.
Testing for myasthenia gravis
A healthcare professional can perform simple tests in the office to look for signs of myasthenia gravis. Some examples are discussed below.
Upward gaze test
In this test, you’ll be asked to look up at the ceiling while keeping your head and neck in a neutral position. If you have myasthenia gravis, your eyelids will start to droop after about a minute.
Ice pack test
Here, you’ll open your eyes wide and measure the distance between your upper and lower eyelids. Then you’ll place an ice pack over your eyelids for 2 minutes. Afterward, the healthcare professional will remeasure the distance between your upper and lower eyelids. If the distance between them has gone up, this can be a sign of myasthenia gravis.
The healthcare professional will order additional blood and imaging tests. The combination of these tests can help determine whether or not you have myasthenia gravis.
Frequently asked questions
Myasthenia gravis can affect anyone of any race or ethnicity. In women, it’s more common before the age of 40. In men, it’s more common after age 50. It’s less common in children and adolescents.
Myasthenia gravis is unlikely to cause weight gain. But this can be a side effect of certain myasthenia gravis treatments, like corticosteroids. Also, people with myasthenia gravis might also struggle to keep up an exercise routine due to limb weakness. This could make weight management more challenging.
A myasthenic crisis is when weakness of the respiratory muscles prevents someone from breathing on their own. This means they would need a machine to breathe for them, whether through a tube in the airway or a mask on the face. But a crisis usually comes on gradually, allowing time to get medical attention. It’s often triggered by an illness, stress, or surgery. But sometimes no trigger can be identified.
The bottom line
Myasthenia gravis is an autoimmune condition that leads to muscle weakness. It starts off very slowly, and early symptoms can be hard to spot. About half of all people with myasthenia gravis start off with weakness in the small muscles of their eyes. Early symptoms of myasthenia gravis include vision changes like blurry or double vision and eyelid drooping.
Seek medical care if you think you have symptoms of myasthenia gravis. Finding myasthenia gravis early lets you start treatment sooner, when the condition is easier to get under control.
Why trust our experts?
References
Claytor, B., et al. (2023). Myasthenic crisis. Muscle & Nerve.
Dresser, L., et al. (2021). Myasthenia gravis: Epidemiology, pathophysiology and clinical manifestations. Journal of Clinical Medicine.
Estephan, E. d. P., et al. (2022). Myasthenia gravis in clinical practice. Arquivos de Neuro-Psiquiatria.
Giannoccaro, M. P., et al. (2020). Comparison of ice pack test and single-fiber EMG diagnostic accuracy in patients referred for myasthenic ptosis. Neurology.
Muscular Dystrophy Association. (n.d.). Myasthenia gravis (MG).
Myasthenia Gravis Foundation of America. (2018). Voice & speech: Effects of myasthenia gravis on voice, speech, and swallowing.
National Institute of Neurological Disorders and Stroke. (2024). Myasthenia gravis.
Neurosigns. (2017). Myasthenic snarl.
Sansoni, J., et al. (2023). Clinical features, treatments, their impact, and quality of life for Myasthenia Gravis patients in Australia. Journal of Clinical Neuroscience.
Thyparampil, P. (2024). Myasthenia gravis. EyeWiki.
