How does the immune system work? The immune system consists of organs, cells, tissues, and proteins. Together, they carry out bodily processes to fight off pathogens and does a remarkable job of defending you against disease-causing microorganisms. But sometimes it fails- a germ invades successfully and makes you sick. Try few lifestyle strategies to make your immune system stronger: > Eat a diet high in fruits and vegetables > Exercise regularly > Maintain a healthy weight > Get adequate sleep