Quick answer. Myasthenia gravis is an autoimmune condition that causes muscle weakness which gets worse with activity and improves with rest. It is treatable, but sudden weakness of the breathing or swallowing muscles (a myasthenic crisis) is a medical emergency – call 995.
Myasthenia gravis is a long-term autoimmune condition in which the immune system disrupts the signals between nerves and muscles, leading to muscle weakness that characteristically worsens with use and recovers with rest. In Singapore it is seen across both younger women and older men, and it is one of the more recognisable causes of fluctuating droopy eyelids and double vision.
Although the name sounds alarming, most people with myasthenia gravis can be managed well with medication and lead full lives. This guide explains what the condition is, the symptoms to watch for, how neurologists diagnose it, the treatments available, and the urgent warning signs that mean you should not wait.
At a glance
| Type | Muscles affected | What it tends to mean |
|---|---|---|
| Ocular | Eyelids and eye-moving muscles | Droopy lids and double vision; may stay confined to the eyes |
| Generalised | Face, throat, limbs, breathing | Weakness spreads beyond the eyes; needs closer monitoring |
| Bulbar-predominant | Chewing, swallowing, speech | Slurred speech, choking risk; flag to your doctor early |
| Crisis | Breathing muscles | Breathing failure – a medical emergency, call 995 |
| Stable / in remission | Variable | Symptoms controlled on treatment; ongoing review |
What is myasthenia gravis?
Myasthenia gravis is an autoimmune disorder where antibodies block or damage the receptors at the neuromuscular junction – the point where a nerve tells a muscle to contract. Because the signal does not get through reliably, the muscle tires quickly. The hallmark is fatigable weakness: a muscle works at first, then weakens the more it is used, and recovers after rest.
It can begin at any age. A common pattern in Singapore and worldwide is younger adults, more often women, and a separate group of older adults, more often men. The thymus gland (in the chest) is often involved, and some people have an associated thymus growth called a thymoma. It is not contagious and it is not inherited in a simple way.
Symptoms & signs
Symptoms typically come and go and are usually worse later in the day or after exertion. They may include:
- Drooping of one or both upper eyelids (ptosis)
- Double or blurred vision
- Weak, tired-sounding or slurred speech
- Difficulty chewing and swallowing, sometimes choking on food or drink
- A weak smile or facial expression
- Weakness in the neck, arms, hands or legs – for example difficulty lifting the arms, climbing stairs or holding the head up
- Shortness of breath, especially on exertion or when lying flat
Many people first notice the eye symptoms. In some, the condition stays limited to the eyes; in others it spreads to other muscle groups over weeks to months.
Causes & risk factors
Myasthenia gravis is caused by the immune system producing antibodies (most commonly against the acetylcholine receptor) that interfere with nerve-to-muscle signalling. Why this happens is not fully understood. Recognised associations and triggers include:
- Abnormalities of the thymus gland, including thymoma
- Other autoimmune conditions, such as thyroid disease or rheumatoid arthritis
- Infections, physical or emotional stress, surgery and pregnancy, which can unmask or worsen symptoms
- Certain medicines, which can aggravate weakness – always tell any treating doctor that you have the condition
It is not caused by anything you did, and lifestyle does not bring it on.
How it's diagnosed
A neurologist makes the diagnosis by combining your history with examination and tests, because the fluctuating nature of the weakness can be missed on a single visit. Tests may include:
- Blood tests for the antibodies linked to myasthenia gravis (such as acetylcholine receptor or MuSK antibodies)
- Nerve and muscle studies – repetitive nerve stimulation or single-fibre electromyography (EMG) to show the signalling problem
- A CT or MRI scan of the chest to look at the thymus gland for a thymoma
- Bedside tests such as observing for fatigable eyelid drooping, and an ice-pack test on the eyelid
- Checks for associated conditions, for example thyroid function
Treatment options
Myasthenia gravis cannot usually be cured, but treatment controls symptoms well for most people and aims for minimal or no symptoms. Options your neurologist may use include:
- Symptom-relief medicines (acetylcholinesterase inhibitors such as pyridostigmine) that improve nerve-to-muscle signalling
- Immune-modifying treatment such as corticosteroids and steroid-sparing immunosuppressants to calm the underlying autoimmune process
- Thymus surgery (thymectomy), particularly if a thymoma is present and sometimes to improve overall control
- Rapid treatments for severe flares – intravenous immunoglobulin (IVIG) or plasma exchange – usually in hospital
- Newer targeted (biologic) therapies in selected cases
Treatment is tailored to you and adjusted over time. Regular neurology follow-up matters, because flares can be triggered by infections, stress or certain drugs.
When to see a doctor & which specialist
See a doctor if you have unexplained, fluctuating muscle weakness, droopy eyelids or double vision, especially weakness that gets worse with use and better with rest. Early assessment helps because the condition can spread beyond the eyes.
Call 995 or go to A&E immediately if there is difficulty breathing, or weakness of swallowing with choking and inability to clear secretions. This can signal a myasthenic crisis, where the breathing muscles fail, and it is life-threatening and needs urgent hospital care. Sudden worsening of generalised weakness should also be treated as urgent.
Myasthenia gravis is managed by a neurologist, often with input from other specialists. You can find one through our directory of neurologists in Singapore.
Living well with myasthenia gravis
Most people manage the condition well with the right treatment and some practical adjustments. Pacing activities and resting before they tire helps, since weakness builds with use and improves with rest. Heat, infections, emotional stress and poor sleep can make symptoms worse, so it helps to plan demanding tasks for earlier in the day when you are stronger.
- Take your medicines on time, as timing can affect how well your muscles work through the day.
- Always tell any doctor, dentist or pharmacist that you have myasthenia gravis, because some medicines can worsen weakness.
- Keep up with vaccinations and treat infections early, as illness can trigger a flare.
- Carry information about your condition in case of an emergency.
What to expect at the appointment
Because the weakness comes and goes, it helps to note when symptoms are worst, what brings them on, and how they respond to rest. The neurologist may arrange blood tests for specific antibodies, nerve and muscle studies, and a chest scan to check the thymus gland.
Costs and financing in Singapore
Specialist review, tests and any hospital treatment such as thymus surgery are available at public hospitals with subsidies for eligible patients. MediSave can generally be applied towards hospitalisation and surgery within set limits. Ask your care team which schemes apply to your situation.
Common questions
Can myasthenia gravis be cured?
It is usually a long-term condition rather than one that is cured, but treatment controls symptoms well for most people, and some achieve long periods with minimal or no symptoms.
What is a myasthenic crisis?
It is severe weakness of the breathing or swallowing muscles. It is a medical emergency, call 995 or go to A&E immediately.
Related guides
- Best Neurology Clinics in Singapore — our editorial shortlist
- neurology clinics directory
- Hyperparathyroidism
- Cushing's syndrome
- Ovarian cancer
- Endometrial cancer
- Bartholin's cyst
Sources
- NHS – Myasthenia gravis
- Mayo Clinic – Myasthenia gravis
- HealthHub Singapore
- SingHealth – Conditions and treatments
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