If you've been traveling or hiking or fishing and are now sick, your doctor needs all the details to diagnose both rare and common viruses. Your body's defence mechanism needs nourishment. Eat at least 5 servings of fruits and vegetables a day. Don't Overdo It. Get plenty of sleep and avoid stress to maintain immune function.
Regular exercise boosts the immune system.
Garlic and echinacea are promising boosters to the immune system.