“I have left-side facial numbness, weakness, blurred vision, and headache. Are these symptoms of myasthenia gravis, or should I be concerned about a stroke?” asked an MGteam member.

Myasthenia gravis (MG) is an autoimmune disorder that causes weakness of all muscles — but mostly those of the eyes, face, arms, and legs. Up to 60 percent of those with MG report some facial weakness. One of the most common symptoms is a mask-like appearance when the person can appear emotionless, even when they’re not.

These changes can make it harder to express yourself and communicate with others. But with better management of MG, many people have reported getting their smiles back. Here are some specific ways MG can affect the ability to smile or show emotion through facial expressions.

1. A Smile That Gets Tired

MG causes muscle weakness and fatigue — including in facial muscles used for smiling and other facial expressions. If you’re at a meeting or at a social event where you need to smile frequently, you may notice your facial muscles getting tired, making it harder to keep smiling as the day goes on.

“I pay dearly for overdoing it. … My daughter tells me she knows right away when I have done too much. My facial muscles must weaken, she says she sees my face change,” shared an MGteam member.

Some people with MG first notice they’re smiling less than before after seeing photographs of themselves. They remember feeling happy and trying to smile but struggled to show it.

As with other symptoms of MG, facial weakness may be better or worse at different times. For example, you may notice your symptoms are harder to control at the end of a long day or when you’re tired from other activities.

2. A ‘Droopy’ Smile

One of the main symptoms of MG is ptosis (drooping eyelids). For some people, this effect extends to other facial muscles.

If your face starts to droop, it might not look as even, and forming a full smile can become harder. As a result, people may misread your emotions, thinking you’re upset, bored, or dissatisfied. Verbally communicating your mood by reassuring others when you’re happy or having a good time can make it easier for them to understand your mood.

3. A Muted Grin

Sometimes, the facial changes associated with MG can be subtle. Researchers have started using advanced technology to measure slight changes to the face that could help diagnose and measure the severity of MG. Specifically, they noted that the “pulling of the lip corners” is less pronounced in people with MG. Neurologists are getting better at spotting facial changes caused by MG by using advanced computer tools like machine learning and artificial intelligence.

People who had a large grin in the past may not have as big of a smile due to muscle weakness from MG. This change can make others think you’re not as happy, even when you are. As technology continues to advance, new solutions that improve the diagnosis and early treatment of MG are likely to help keep symptoms under control.

4. A One-Sided Smile

MG doesn’t necessarily affect your entire smile. Sometimes, it just affects one side of the mouth or face. As a result, people with MG may have trouble determining if another problem, such as a stroke, is actually causing their symptoms.

“MG can be one-sided,” said one MGteam member. “It can also present numbness. I’ve had a couple of flares that have presented that way. It’s a bit like a rollercoaster. I ended up in the emergency room, thinking it was a stroke. Two days and $29,000 later, there was no stroke. MG presents in so many ways. … I’m still learning what MG means for me. I keep an MG diary. It helps.”

Another shared, “The muscles on the one side of my face are very weak because I had Bell’s palsy before.”

Some people have symptoms that come on quickly and unexpectedly, while others have less dramatic changes that are subtle over time. When in doubt about the cause of facial paralysis or other symptoms, call your health care provider to decide if you should go to the hospital.

MG Social and Emotional Challenges

MG is often associated with feelings of embarrassment, loss of control, and social isolation. You may become self-conscious about seeming different than others or frustrated when people can’t read your nonverbal cues as easily.

Teaching friends, family, and co-workers about MG and how it affects facial expressions helps everyone understand and be more empathetic, which can lessen social stigma and clear up any misconceptions. In addition, meeting with a mental health care provider and connecting with a support group can help you find positive coping strategies.

Fortunately, new tools are being developed to help people with MG get the right diagnosis faster so they can start treatment and enjoy more normal lives. It’s important to remain patient and keep looking for answers to the issues affecting your everyday life. You may have to experiment with various MG treatments to learn what works for you. On MGteam, there are several stories of people with MG who were able to “get their smiles back” after finding the right treatment.

With the support of your health care team, most people with MG can experience some symptom improvement. Prolonging periods of remission (or low symptoms) and shortening flare-ups can reduce MG’s impact on your social interactions, self-esteem, and quality of life.

Talk With Others Who Understand

MGteam is the social network for people with the autoimmune disease myasthenia gravis. On MGteam, members come together to ask questions, give advice, and share their experiences with others who understand life with myasthenia gravis.

Has MG affected muscle strength in your face? Aside from impacts on your smile, have you noticed other symptoms like droopy eyelids, double vision, difficulty chewing, or shortness of breath? Share your story in the comments below, or start a conversation by posting to your Activities feed.