15 Symptoms of Myasthenia Gravis

2. Double Vision

Myasthenia gravis often appears early in myasthenia gravis. Weak eye muscles prevent the eyes from staying aligned, so each eye may point in a slightly different direction, causing the brain to perceive two images of a single object.

The symptom usually worsens after activities that strain the eyes, such as reading, watching television, or using a computer, and often improves with rest. Because symptoms can fluctuate throughout the day, double vision may initially confuse people or make it difficult to recognize. Drooping eyelids may occur alongside double vision, as the eyelid muscles can weaken similarly.

Closing one eye may temporarily reduce the double vision, but it does not address the underlying muscle weakness. Double vision can affect daily tasks like driving, walking down stairs, or focusing on small print. Some people notice that the two images appear side by side or slightly tilted, depending on which eye muscles are more affected.

3. Difficulty Swallowing

Difficulty swallowing, also called trouble swallowing, is a common symptom of myasthenia gravis. Weak mouth and throat muscles reduce the ability to move food and liquids efficiently from the mouth into the stomach. A person may notice that food feels stuck in the throat, require longer chewing, or take smaller bites.

Swallowing liquids, especially thin drinks like water, can also become difficult. Common signs include choking or coughing during meals, food coming back up into the nose, a wet or gurgling voice after swallowing, and taking a long time to finish meals. Muscle weakness often worsens later in the day or after repeated use, so swallowing may seem normal at the start of a meal but become harder as eating continues.

Difficulty swallowing can range from mild to severe and may fluctuate throughout the day depending on muscle fatigue. In more serious cases, small amounts of food or liquid can enter the airway instead of the stomach, increasing the risk of chest infections.

4. Changes in Voice

Myasthenia gravis can weaken the muscles that control speech, reducing the ability of the throat and mouth muscles to manage airflow and sound. This makes the voice soft, quiet, or hard to hear. A person may develop a nasal tone, sound hoarse, breathy, or slurred after talking for a short time.

Common voice changes include a weak or fading voice, a nasal or “stuffy” quality, slurred or unclear speech, and trouble speaking loudly. These changes often worsen as the day progresses or after long conversations because the muscles tire easily. Rest can temporarily improve the voice, though voice problems may also appear alongside trouble chewing or swallowing.

Speech that starts clear in the morning can become harder to understand by evening. In more severe cases, weakness of the breathing muscles may make the voice sound strained. Long sentences may become harder to finish clearly because the muscles involved in speech fatigue before the thought is completed.

5. Weak Cough

A weak cough can occur when myasthenia gravis affects the muscles in the chest and throat, which push air out of the lungs. When these muscles lose strength, the cough loses force, making it harder to clear mucus, food particles, and germs from the airways. A person may feel mucus stuck in the chest and struggle to expel it.

Muscle weakness often worsens after activity and improves with rest, so by the end of the day, the cough may sound softer and less effective. A weak cough can allow mucus to build up in the lungs, increasing the risk of chest infections. Some people may also choke more easily if food or liquid enters the airway and cannot be expelled effectively.

Signs associated with a weak cough include frequent throat clearing, repeated chest infections, shortness of breath, and difficulty clearing mucus. Doctors may suggest treatments to improve muscle strength or regulate the immune system, such as immune therapies. Breathing support and guided exercises can also help protect the lungs when coughing becomes too weak.

6. Difficulty Breathing

Myasthenia gravis can weaken the muscles that control breathing, including the diaphragm and chest muscles that help the lungs expand and contract. When these muscles lose strength, breathing becomes more difficult. A person may notice shortness of breath during simple tasks, such as climbing stairs, walking short distances, or talking for long periods.

Some people feel more breathless when lying flat. Breathing problems often worsen after activity and may improve with rest, but weakness can return later in the day. Signs of breathing muscle weakness include short, shallow breaths, trouble taking a deep breath, feeling air hunger, a weak cough, and frequent chest infections due to poor airway clearing.

In severe cases, breathing muscles can become too weak to work effectively, a condition called a myasthenic crisis. This may cause rapid breathing, difficulty speaking full sentences, or visible strain in the neck and chest while breathing, which requires urgent medical care.

7. Muscular Weakness

Muscular weakness is the main symptom of myasthenia gravis. It affects voluntary muscles the muscles a person controls intentionally, including those in the eyes, face, arms, legs, and throat. Weakness often worsens with activity and improves after rest. Small muscle groups are usually affected first, making it difficult to hold the head up, lift objects, climb stairs, or perform simple daily tasks such as brushing hair or standing from a seated position with the arms are weaker than the legs.

Some people develop a slow or unsteady walk because their muscles tire easily, while others may struggle to maintain proper posture. Muscle weakness can fluctuate from day to day and may worsen with stress, illness, or lack of sleep. In more serious cases, weakness can spread to the muscles that support breathing, which requires urgent medical care.

8. Malaise

Malaise is a general feeling of being unwell or run down. In myasthenia gravis, a person may not initially notice clear muscle weakness but instead feel tired, low on energy, or “not like themselves.” This feeling often stems from muscle fatigue.

Muscles weaken more with activity and improve after rest, so energy levels tend to decline as the day progresses, especially after repeated tasks. Common features of malaise in myasthenia gravis include low energy even after a full night of sleep, reduced stamina during daily tasks, a sense of physical heaviness, and feeling worse during stress or illness.

Malaise can affect mood and daily life. A person may avoid social events or physical activity because they anticipate feeling worn out. Simple chores, such as brushing hair or climbing stairs, may feel harder than usual. This symptom may also appear alongside other signs of myasthenia gravis, including droopy eyelids, slurred speech, trouble chewing, or shortness of breath when breathing muscles weaken.

9. Trouble Talking

Myasthenia gravis can weaken the muscles that control speech, including the tongue, lips, and throat. When these muscles lose strength, a person’s voice may sound soft, slurred, or unclear, and others may notice that they sound tired when speaking.

Speech problems often worsen after long conversations. The voice may start strong but fade over time, though rest can temporarily improve clarity. Some people develop a nasal or hoarse tone, words may run together, and certain sounds may take more effort to pronounce.

Common speech changes include slurred words, a quiet or weak voice, a nasal sound, and trouble forming clear sentences. These issues often fluctuate, worsening at the end of the day or after activity, and may be amplified by stress or illness.

Trouble talking can affect daily life. Simple tasks like making phone calls or speaking in a group may feel difficult. When speech muscles grow very weak, these problems may also be associated with difficulty chewing or swallowing.

10. Sensitivity to Medication

Myasthenia gravis can cause strong reactions to certain medicines, which may increase muscle weakness or trigger new symptoms. Even a small dose can cause problems in some cases. Medicines that may worsen symptoms include certain antibiotics, beta blockers used for heart conditions, some anti-seizure medicines, magnesium-containing products, certain heart rhythm medicines, and some cholesterol-lowering medicines.

These drugs interfere with how nerves send signals to muscles. In myasthenia gravis, nerve signals are already weakened, so further disruption can make muscles more tired or weak. A person may notice drooping eyelids, increased trouble swallowing, or shortness of breath after starting a new medicine. Symptoms can appear within hours or days and often improve once the medicine is stopped under medical guidance.

Because of this sensitivity, healthcare providers review all medicines carefully, including over-the-counter drugs and supplements, to prevent worsening symptoms. Even routine treatments, such as some muscle relaxants used during procedures, may require extra caution because they can intensify weakness.

11. Slow Movement

Slow movement can occur when myasthenia gravis weakens the voluntary muscles used for walking, lifting, or turning the head. When these muscles tire easily, movements become slower and less steady. A person may notice that daily tasks take longer than before.

Simple actions like getting up from a chair, climbing stairs, or reaching for objects may feel delayed. This is not due to joint pain or stiffness but occurs because the muscles cannot respond with normal strength. Repeated use worsens muscle weakness. After walking a short distance, the legs may feel heavy, and holding the arms up can slow movements further. Rest usually helps, allowing strength to improve temporarily.

Slow movement can also affect the neck and face. The head may be moved carefully to prevent it from dropping forward, and facial movements such as smiling or blinking may seem reduced or delayed. This symptom can fluctuate from day to day and often becomes more noticeable during stress, illness, or lack of sleep.

12. Weak Grip

A weak grip is a common sign of myasthenia gravis. It affects the muscles in the hands and fingers, making simple tasks more tiring. A person may struggle to hold items like a cup, phone, or pen, and objects can slip from their hands without warning.

Muscle strength may seem normal at first, but after a short period of activity, the hands feel heavy or shaky. Rest usually helps restore strength temporarily, but weak grip can make daily tasks harder. Buttoning clothes, opening jars, carrying groceries, or writing for long periods may require more effort.

The weakness may not affect both hands equally; one hand can feel weaker than the other. Symptoms often fluctuate during the day and tend to worsen with fatigue. In myasthenia gravis, the immune system disrupts signals between nerves and muscles. This reduces the muscles’ ability to contract with full strength, causing hand muscles to lose power during use but regain strength after rest.

13. Apnea

Apnea is a pause in breathing. In myasthenia gravis, weak breathing muscles, including those in the chest and throat, can make it difficult to take deep breaths, and in severe cases, breathing may stop for short periods. Breathing problems often worsen after activity or at the end of the day. Infection or high stress can also trigger symptoms.

Weak chest muscles cannot move enough air in and out of the lungs, reducing oxygen exchange. Warning signs include shortness of breath while resting, trouble breathing when lying flat, shallow or slow breathing, sudden pauses in breathing, and difficulty speaking in full sentences. In severe cases, a myasthenic crisis can occur, during which breathing muscles become too weak to support normal breathing.

14. Loss of Weight

Unplanned weight loss can occur in people with myasthenia gravis. Muscle weakness often affects the face, jaw, and throat first, making chewing and eating tiring and slow. When chewing becomes difficult, a person may avoid solid foods, eat smaller portions, or skip meals.

Trouble swallowing can also contribute, as food may feel stuck or cause coughing or choking, reducing the desire to eat. Other symptoms can worsen the problem, including jaw fatigue during meals, slurred speech that makes social meals stressful, shortness of breath while eating, and weak neck muscles that make it hard to hold the head up at the table.

Some people may also burn more energy because their muscles work harder to perform even simple tasks. Activities like brushing teeth or climbing stairs can cause fatigue, and this constant effort can contribute to gradual weight loss. Weight changes often develop slowly over weeks or months and may become more noticeable during periods when symptoms worsen.

15. Myasthenic Crisis

Myasthenic crisis is a severe, life-threatening form of muscle weakness that occurs when the muscles controlling breathing become too weak to function properly. During a crisis, a person may feel short of breath or unable to take deep breaths. They may struggle to speak full sentences or lie flat without feeling breathless.

Trouble swallowing may also worsen, increasing the risk of choking. Common warning signs include fast, shallow breathing; severe weakness in the neck or chest; difficulty holding the head up; blue lips or fingertips from low oxygen; and extreme fatigue that develops quickly. A crisis can be triggered by sudden worsening of myasthenia gravis, inappropriate medication doses, infections, or major stress on the body.

Doctors treat myasthenic crises in a hospital. Many people require breathing support with a ventilator until their muscles regain strength. Treatments may include immune therapies that reduce harmful antibodies in the blood, such as plasma exchange or intravenous immune globulin.