The following symptoms affect people during the acute phase of polio infection:
- In mild, or abortive polio: headache, nausea, vomiting for as many as three days—symptoms that one can generally mistake for a bad case of the flu.
- In nonparalytic polio: similar to mild cases with the addition of moderate fever, stiff back and neck, fatigue and muscle pain.
- In paralytic polio: tremor, muscle weakness, fever, stiffness, constipation, muscle pain, and difficulty swallowing.
Symptoms of post-polio syndrome include:
- Onset of new muscle weakness
- Joint pain and possible fatigue
- Muscle atrophy and cold intolerance
- In severe cases, difficulty swallowing and extended periods of fatigue
