Guillain-Barre syndrome is a serious disorder that occurs when the body's defense (immune) system mistakenly attacks part of the nervous system. This leads to nerve inflammation that causes muscle weakness, which continues to get worse.

Guillain-Barre syndrome is an autoimmune disorder. The exact cause of Guillain-Barre syndrome is unknown. The syndrome may occur at any age, but is most common in people of both sexes between the ages 30 and 50. It often follows a minor infection, usually a respiratory (lung) infection or gastrointestinal (gut) infection. Usually, signs of the original infection have disappeared before the symptoms of Guillain-Barre begin.

Guillain-Barre syndrome causes inflammation that damages parts of nerves. This nerve damage causes tingling, muscle weakness, and paralysis. The inflammation usually affects the nerve's covering (myelin sheath). Such damage is called demyelination. Demyelination slows nerve signaling. Damage to other parts of the nerve can cause the nerve to stop working.

Guillain-Barre syndrome may occur along with viral infections such as:

• Mononucleosis
• AIDS
• Herpes simplex

It may also occur with other medical conditions such as systemic lupus erythematosus or Hodgkin's disease.

Some people may get Guillain-Barre syndrome after a bacterial infection, certain vaccinations (such as rabies and swine flu), and surgery.

Symptoms of Guillain-Barre get worse very quickly. It may take only a few hours to reach the most severe symptoms.

Muscle weakness or the loss of muscle function (paralysis) affects both sides of the body.  If the muscle weakness starts in the legs and then spreads to the arms, it is called ascending paralysis.

Patients may notice tingling, foot or hand pain, and clumsiness. As the loss of muscle function gets worse, the patient may need breathing assistance.

Typical symptoms include:

• Muscle weakness or loss of muscle function (paralysis)
  • Weakness begins in the feet and legs and may move up to the arms and head
  • May get worse over 24 to 72 hours
  • May start in the arms and move downward
  • May begin in the arms and legs at the same time
  • May occur in the nerves of the head only
  • In mild cases, weakness or paralysis may not occur
• Uncoordinated movement
• Sensation changes
• Numbness, decreased sensation
• Tenderness or muscle pain (may be a cramp-like pain)

Additional symptoms may include:

• Blurred vision
• Difficulty moving face muscles
• Clumsiness and falling
• Palpitations (sensation of feeling heartbeat)
• Muscle contractions

Emergency symptoms (seek immediate medical help):

• Difficulty swallowing
• Drooling
• Difficulty breathing
• Breathing, may temporarily stop
• Can't take a deep breath
• Fainting

A history of increasing muscle weakness and paralysis may indicate Guillain-Barre syndrome, especially if there was a recent illness.

A medical exam may show muscle weakness and problems with involuntary (autonomic) body functions such as blood pressure and heart rate.

There may be signs of decreased breathing (caused by paralysis of the breathing muscles), and a decrease in certain arm and leg reflexes.

The following tests may be ordered:

• NCV (nerve conduction velocity) shows nerve damage.
• EMG  tests the electrical activity in muscles. It may shows that nerves do not react properly to stimulation. 
• CSF (cerebrospinal fluid) may have increased levels of protein without an increase in white blood cells.
• ECG may show heart problems in some cases.