Myasthenia gravis, sometimes called MG, is a chronic (long-lasting) disease that causes weakness in your voluntary muscles. The voluntary muscles are the ones that you can control. They include the muscles you use for:
You can also have weakness in other muscles. This weakness gets worse with activity, and better with rest.
Myasthenia gravis is a type of autoimmune disease. In autoimmune diseases, your immune system attacks the healthy cells of your organs and tissues by mistake.
Myasthenia gravis is caused by an error in how nerve signals are sent to muscles. These signals get blocked at the nerve-muscle junction. This junction is the place where the nerve endings connect with the muscles they control.
Normally, this is how the signals work:
But in someone with myasthenia gravis, the body's own immune system makes antibodies that block the binding of acetylcholine to the muscle. This makes the muscles weaker.
The thymus gland, which is part of your immune system, may play a role in myasthenia gravis. Normally, your thymus gland is active and growing when you are a child. It makes white blood cells to fight infections. At puberty, it starts getting smaller and is replaced by fat. It is usually small by the time you are an adult. But in many adults with myasthenia gravis, the thymus gland stays large. And some people with myasthenia gravis can get thymomas, which are tumors of the thymus. The are usually benign (not cancer), but they can sometimes become cancerous.
Although myasthenia gravis can affect people of any age, it is most common in young adult women (under age 40) and older men (over age 60). It is usually not inherited (passed down in families).
Myasthenia gravis normally does not affect infants. But if you are pregnant and have myasthenia gravis it's possible to pass the antibodies to your fetus. The baby can then be born with neonatal myasthenia. This condition is usually temporary, and the symptoms typically go away within two to three months after birth.
The symptoms of myasthenia gravis will depend on which muscles are affected. The symptoms often include:
Different people have different levels of muscle weakness. And the weakness can vary from day to day. Some days it might be mild, and other days it might be worse. Physical activity often makes the muscle weakness worse.
Some people with myasthenia gravis can get severe weakness that affects the muscles that control breathing. This is called a myasthenic crisis, and it is a life-threatening emergency.
There are many other conditions that can cause muscle weakness, so myasthenia gravis can be hard to diagnose. To find out if you have myasthenia gravis, your health care provider:
There is no cure for myasthenia gravis, but treatments that can improve muscle weakness and help with symptoms. They include:
Lifestyle changes may be helpful for some people. The changes could include regular gentle exercise, getting enough rest, and eating healthy foods.
Some people with myasthenia gravis go into remission. This means that they do not have symptoms. The remission is usually temporary, but sometimes it can be permanent.
NIH: National Institute of Neurological Disorders and Stroke
","Myasthenia gravis is a disorder that causes weakness of the skeletal muscles, which are muscles that the body uses for movement. The weakness most often starts in the muscles around the eyes, causing drooping of the eyelids (ptosis) and difficulty coordinating eye movements, which results in blurred or double vision. In a form of the disorder called ocular myasthenia, the weakness remains confined to the eye muscles. In most people with myasthenia gravis, however, additional muscles in the face and neck are affected. Affected individuals may have unusual facial expressions, difficulty holding up the head, speech impairment (dysarthria), and chewing and swallowing problems (dysphagia) that may lead to choking, gagging, or drooling.~Other muscles in the body are also affected in some people with myasthenia gravis. The muscles of the arms and legs may be involved, causing affected individuals to have changes in their gait or trouble with lifting objects, rising from a seated position, or climbing stairs. The muscle weakness tends to fluctuate over time; it typically worsens with activity and improves with rest.~Weakness of the muscles in the chest wall and the muscle that separates the abdomen from the chest cavity (the diaphragm) can cause breathing problems in some people with myasthenia gravis. About 10 percent of people with this disorder experience a potentially life-threatening complication in which these respiratory muscles weaken to the point that breathing is dangerously impaired, and the affected individual requires ventilation assistance. This respiratory failure, called a myasthenic crisis, may be triggered by stresses such as infections or reactions to medications.~People can develop myasthenia gravis at any age. For reasons that are unknown, it is most commonly diagnosed in women younger than age 40 and men older than age 60. It is uncommon in children, but some infants born to women with myasthenia gravis show signs and symptoms of the disorder for the first few days or weeks of life. This temporary occurrence of symptoms is called transient neonatal myasthenia gravis."],"subClassOf":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C2362500"],"parents":[{"id":"http://purl.bioontology.org/ontology/MEDLINEPLUS/C2362500","notation":"C2362500","semanticType":["http://purl.bioontology.org/ontology/STY/T022"],"cui":["C2362500"],"prefLabel":"Brain and Nerves","subClassOf":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C1456590","http://www.w3.org/2002/07/owl#Thing"],"label":[],"prefLabelXl":[],"altLabelXl":[],"hiddenLabelXl":[],"synonym":[],"definition":[],"obsolete":false,"prefixIRI":null,"xref":null,"inScheme":[],"created":null,"modified":null,"@id":"http://purl.bioontology.org/ontology/MEDLINEPLUS/C2362500","@type":"http://www.w3.org/2002/07/owl#Class","links":{"self":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500","ontology":"https://data.bioontology.org/ontologies/MEDLINEPLUS","children":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/children","parents":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/parents","descendants":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/descendants","ancestors":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/ancestors","instances":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/instances","tree":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/tree","notes":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/notes","mappings":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500/mappings","ui":"http://bioportal.bioontology.org/ontologies/MEDLINEPLUS?p=classes&conceptid=http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC2362500","@context":{"self":"http://www.w3.org/2002/07/owl#Class","ontology":"http://data.bioontology.org/metadata/Ontology","children":"http://www.w3.org/2002/07/owl#Class","parents":"http://www.w3.org/2002/07/owl#Class","descendants":"http://www.w3.org/2002/07/owl#Class","ancestors":"http://www.w3.org/2002/07/owl#Class","instances":"http://data.bioontology.org/metadata/Instance","tree":"http://www.w3.org/2002/07/owl#Class","notes":"http://data.bioontology.org/metadata/Note","mappings":"http://data.bioontology.org/metadata/Mapping","ui":"http://www.w3.org/2002/07/owl#Class"}},"@context":{"@vocab":"http://data.bioontology.org/metadata/","label":"http://www.w3.org/2000/01/rdf-schema#label","prefLabel":"http://www.w3.org/2004/02/skos/core#prefLabel","prefLabelXl":"http://www.w3.org/2008/05/skos-xl#prefLabel","altLabelXl":"http://www.w3.org/2008/05/skos-xl#altLabel","hiddenLabelXl":"http://www.w3.org/2008/05/skos-xl#hiddenLabel","synonym":"http://www.w3.org/2004/02/skos/core#altLabel","definition":"http://www.w3.org/2004/02/skos/core#definition","obsolete":"http://www.w3.org/2002/07/owl#deprecated","notation":"http://www.w3.org/2004/02/skos/core#notation","prefixIRI":"http://data.bioontology.org/metadata/prefixIRI","subClassOf":"http://www.w3.org/2000/01/rdf-schema#subClassOf","semanticType":"http://bioportal.bioontology.org/ontologies/umls/hasSTY","cui":"http://bioportal.bioontology.org/ontologies/umls/cui","xref":"http://www.geneontology.org/formats/oboInOwl#hasDbXref","inScheme":"http://www.w3.org/2004/02/skos/core#inScheme","created":"http://purl.org/dc/terms/created","modified":"http://purl.org/dc/terms/modified","@language":[]}}],"label":[],"obsolete":false,"prefixIRI":null,"xref":null,"inScheme":[],"created":null,"modified":null,"memberOf":[],"altLabelXl":[],"hiddenLabelXl":[],"prefLabelXl":[],"isInActiveScheme":[null],"isInActiveCollection":[],"properties":{"http://www.w3.org/2004/02/skos/core#altLabel":["Myasthenia Gravis","Myasthenia gravis"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/DB_XR_ID":["GTR:C0026896~ICD-10-CM:G70.00~ICD-10-CM:G70.01~ICD-10-CM:P94.0~MeSH:D009157~OMIM:159400~OMIM:254200~OMIM:607085~SNOMED CT:91637004"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/mapped_from":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C0026896"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/INHERITANCE":["u:Pattern unknown"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/mapped_to":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C0026896"],"http://www.w3.org/1999/02/22-rdf-syntax-ns#type":["http://www.w3.org/2002/07/owl#Class"],"http://bioportal.bioontology.org/ontologies/umls/tui":["T047"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/related_to":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C0026848","http://purl.bioontology.org/ontology/MEDLINEPLUS/C0004364","http://purl.bioontology.org/ontology/MEDLINEPLUS/C0027868"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/DATE_CREATED":["06/01/1999"],"http://www.w3.org/2004/02/skos/core#notation":["C0026896"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/SOS":["Myasthenia gravis (MG) is an autoimmune disease that weakens the muscles under your control. Find out about MG causes, symptoms, and treatment.https://medlineplus.gov/myastheniagravis.html"],"http://bioportal.bioontology.org/ontologies/umls/hasSTY":["http://purl.bioontology.org/ontology/STY/T047"],"http://bioportal.bioontology.org/ontologies/umls/cui":["C0026896"],"http://www.w3.org/2004/02/skos/core#prefLabel":["MG"],"http://www.w3.org/2004/02/skos/core#definition":["Myasthenia gravis, sometimes called MG, is a chronic (long-lasting) disease that causes weakness in your voluntary muscles. The voluntary muscles are the ones that you can control. They include the muscles you use for:
You can also have weakness in other muscles. This weakness gets worse with activity, and better with rest.
Myasthenia gravis is a type of autoimmune disease. In autoimmune diseases, your immune system attacks the healthy cells of your organs and tissues by mistake.
Myasthenia gravis is caused by an error in how nerve signals are sent to muscles. These signals get blocked at the nerve-muscle junction. This junction is the place where the nerve endings connect with the muscles they control.
Normally, this is how the signals work:
But in someone with myasthenia gravis, the body's own immune system makes antibodies that block the binding of acetylcholine to the muscle. This makes the muscles weaker.
The thymus gland, which is part of your immune system, may play a role in myasthenia gravis. Normally, your thymus gland is active and growing when you are a child. It makes white blood cells to fight infections. At puberty, it starts getting smaller and is replaced by fat. It is usually small by the time you are an adult. But in many adults with myasthenia gravis, the thymus gland stays large. And some people with myasthenia gravis can get thymomas, which are tumors of the thymus. The are usually benign (not cancer), but they can sometimes become cancerous.
Although myasthenia gravis can affect people of any age, it is most common in young adult women (under age 40) and older men (over age 60). It is usually not inherited (passed down in families).
Myasthenia gravis normally does not affect infants. But if you are pregnant and have myasthenia gravis it's possible to pass the antibodies to your fetus. The baby can then be born with neonatal myasthenia. This condition is usually temporary, and the symptoms typically go away within two to three months after birth.
The symptoms of myasthenia gravis will depend on which muscles are affected. The symptoms often include:
Different people have different levels of muscle weakness. And the weakness can vary from day to day. Some days it might be mild, and other days it might be worse. Physical activity often makes the muscle weakness worse.
Some people with myasthenia gravis can get severe weakness that affects the muscles that control breathing. This is called a myasthenic crisis, and it is a life-threatening emergency.
There are many other conditions that can cause muscle weakness, so myasthenia gravis can be hard to diagnose. To find out if you have myasthenia gravis, your health care provider:
There is no cure for myasthenia gravis, but treatments that can improve muscle weakness and help with symptoms. They include:
Lifestyle changes may be helpful for some people. The changes could include regular gentle exercise, getting enough rest, and eating healthy foods.
Some people with myasthenia gravis go into remission. This means that they do not have symptoms. The remission is usually temporary, but sometimes it can be permanent.
NIH: National Institute of Neurological Disorders and Stroke
","Myasthenia gravis is a disorder that causes weakness of the skeletal muscles, which are muscles that the body uses for movement. The weakness most often starts in the muscles around the eyes, causing drooping of the eyelids (ptosis) and difficulty coordinating eye movements, which results in blurred or double vision. In a form of the disorder called ocular myasthenia, the weakness remains confined to the eye muscles. In most people with myasthenia gravis, however, additional muscles in the face and neck are affected. Affected individuals may have unusual facial expressions, difficulty holding up the head, speech impairment (dysarthria), and chewing and swallowing problems (dysphagia) that may lead to choking, gagging, or drooling.~Other muscles in the body are also affected in some people with myasthenia gravis. The muscles of the arms and legs may be involved, causing affected individuals to have changes in their gait or trouble with lifting objects, rising from a seated position, or climbing stairs. The muscle weakness tends to fluctuate over time; it typically worsens with activity and improves with rest.~Weakness of the muscles in the chest wall and the muscle that separates the abdomen from the chest cavity (the diaphragm) can cause breathing problems in some people with myasthenia gravis. About 10 percent of people with this disorder experience a potentially life-threatening complication in which these respiratory muscles weaken to the point that breathing is dangerously impaired, and the affected individual requires ventilation assistance. This respiratory failure, called a myasthenic crisis, may be triggered by stresses such as infections or reactions to medications.~People can develop myasthenia gravis at any age. For reasons that are unknown, it is most commonly diagnosed in women younger than age 40 and men older than age 60. It is uncommon in children, but some infants born to women with myasthenia gravis show signs and symptoms of the disorder for the first few days or weeks of life. This temporary occurrence of symptoms is called transient neonatal myasthenia gravis."],"http://purl.bioontology.org/ontology/MEDLINEPLUS/MP_PRIMARY_INSTITUTE_URL":["National Institute of Neurological Disorders and Stroke http://www.ninds.nih.gov/"],"http://purl.bioontology.org/ontology/MEDLINEPLUS/MP_OTHER_LANGUAGE_URL":["Spanish https://medlineplus.gov/spanish/myastheniagravis.html"],"http://www.w3.org/2000/01/rdf-schema#subClassOf":["http://purl.bioontology.org/ontology/MEDLINEPLUS/C2362500"]},"@id":"http://purl.bioontology.org/ontology/MEDLINEPLUS/C0026896","@type":"http://www.w3.org/2002/07/owl#Class","links":{"self":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896","ontology":"https://data.bioontology.org/ontologies/MEDLINEPLUS","children":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/children","parents":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/parents","descendants":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/descendants","ancestors":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/ancestors","instances":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/instances","tree":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/tree","notes":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/notes","mappings":"https://data.bioontology.org/ontologies/MEDLINEPLUS/classes/http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896/mappings","ui":"http://bioportal.bioontology.org/ontologies/MEDLINEPLUS?p=classes&conceptid=http%3A%2F%2Fpurl.bioontology.org%2Fontology%2FMEDLINEPLUS%2FC0026896","@context":{"self":"http://www.w3.org/2002/07/owl#Class","ontology":"http://data.bioontology.org/metadata/Ontology","children":"http://www.w3.org/2002/07/owl#Class","parents":"http://www.w3.org/2002/07/owl#Class","descendants":"http://www.w3.org/2002/07/owl#Class","ancestors":"http://www.w3.org/2002/07/owl#Class","instances":"http://data.bioontology.org/metadata/Instance","tree":"http://www.w3.org/2002/07/owl#Class","notes":"http://data.bioontology.org/metadata/Note","mappings":"http://data.bioontology.org/metadata/Mapping","ui":"http://www.w3.org/2002/07/owl#Class"}},"@context":{"@vocab":"http://data.bioontology.org/metadata/","label":"http://www.w3.org/2000/01/rdf-schema#label","prefLabel":"http://www.w3.org/2004/02/skos/core#prefLabel","prefLabelXl":"http://www.w3.org/2008/05/skos-xl#prefLabel","altLabelXl":"http://www.w3.org/2008/05/skos-xl#altLabel","hiddenLabelXl":"http://www.w3.org/2008/05/skos-xl#hiddenLabel","synonym":"http://www.w3.org/2004/02/skos/core#altLabel","definition":"http://www.w3.org/2004/02/skos/core#definition","obsolete":"http://www.w3.org/2002/07/owl#deprecated","notation":"http://www.w3.org/2004/02/skos/core#notation","prefixIRI":"http://data.bioontology.org/metadata/prefixIRI","parents":"http://www.w3.org/2000/01/rdf-schema##