Progression of the symptoms may continue for up to four weeks. Recovery is often slow, lasting 6 months to two years. There is no single reliable diagnostic test. A variety of tests are often performed, including nerve conduction studies and tests to measure muscle weakness and sensory changes. Diagnosis is usually made based upon clinical symptoms and exclusion of other possible causes of the ascending paralysis.
Treatment is primarily supportive care, physical therapy and psychologic support.
Ventilatory support may be required in those patients with respiratory failure. An individual with Guillain-Barre Syndrome is not infectious to others. There is no known action which can be taken to prevent Guillain-Barre Syndrome.