Patients may experience infusion-related reactions to IVIg including: headaches, chills, fevers, shortness of breath, and chest pain. If any of these reactions occur, the rate of the infusion is lowered to lessen the effects. Other complaints or side effects are gastrointestinal upset and nausea. Patients may experience aseptic meningitis syndrome, which is a non-infectious inflammation of the meninges (membranes that line the brain and spinal cord) that causes headaches and a stiff neck, but this will go away with increasing fluid intake, rest and Tylenol.