Myasthenia gravis
Autoimmune conditionAntibodies block the signal between nerves and muscles, causing weakness that gets worse with use and improves with rest.
What happens
Most people have antibodies against the receptors muscles use to receive nerve signals. Muscles tire quickly, especially those that control the eyes, face, and throat. About 1 in 10 people with myasthenia gravis has a growth on the thymus gland (thymoma).
Who gets it
Before age 40 it's more common in women; after 60 it's more common in men. It often occurs alongside autoimmune thyroid disease.
Common signs
- One or both eyelids drooping
- Double vision
- Weakness that's worse later in the day or after activity
- Trouble chewing, swallowing, or speaking clearly
- Weak neck, arms, or legs
- Shortness of breath, which can be serious
Labs to ask about
- Acetylcholine receptor and MuSK antibodies
- Nerve and muscle electrical testing (EMG)
- Chest CT to check the thymus
- Thyroid tests
How it's usually treated
- Medicine that strengthens the nerve-to-muscle signal (pyridostigmine)
- Steroids and immune-suppressing medicines
- Surgery to remove the thymus for some people
- IVIG, plasma exchange, or newer biologics for flares
Supportive steps to discuss with your provider
- Some medicines and supplements can worsen weakness, including certain antibiotics, beta-blockers, and magnesium. Check every new one with your care team.
- Plan rest around the times you need your strength most.
- Treat infections promptly. They can trigger flares.
See a doctor promptly if you have
- Trouble breathing or swallowing: call 911 (possible myasthenic crisis)
- Weakness that's getting worse quickly
- New double vision or drooping eyelids
Related conditions
Hashimoto's thyroiditis
The most common cause of an underactive thyroid in the US. The immune system slowly damages the thyroid, so it makes less hormone over time.
Learn more →Graves' disease
The most common cause of an overactive thyroid. Antibodies switch the thyroid 'on' so it makes too much hormone.
Learn more →Lupus
A whole-body autoimmune disease that can inflame the skin, joints, kidneys, blood, heart, lungs, and brain.
Learn more →
Wondering if your symptoms fit a pattern?
Dr. Lesher is a naturopathic doctor who specializes in women's autoimmune and chronic conditions. Since 2020, she has helped more than 900 patients overcome and heal from their conditions.