The first signs of West Nile virus can vary from person to person, and some people may not experience any symptoms at all. However, about 1 in 5 people who are infected develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. These symptoms are similar to those of the flu and can last for several days to a few weeks. In severe cases, the virus can cause encephalitis or meningitis, which can lead to symptoms such as high fever, neck stiffness, muscle weakness, stupor, disorientation, tremors, seizures, paralysis, and coma. People over 60 years of age and those with certain medical conditions are at a higher risk of developing severe illness if infected. If you suspect that you or a family member may have West Nile virus, it is important to talk to a healthcare provider for diagnosis and treatment.