Guillain-Barre syndrome is not hereditary or contagious. What causes GBS is not known; however, in about half of all cases the onset of the syndrome follows a viral or bacterial infection, such as the following:
- Campylobacteriosis (usually from eating undercooked poultry)
- Flu (influenza), common cold
- Gastrointestinal viral infection
- Infectious mononucleosis
- Porphyria (rare disease of red blood cells)
- Viral hepatitis
A small number of cases have been known to occur after a medical procedure, such as minor surgery.
Guillain-Barre syndrome may be an autoimmune disorder in which the body produces antibodies that damage the myelin sheath that surrounds peripheral nerves. The myelin sheath is a fatty substance that surrounds axons. It increases the speed at which signals travel along the nerves.