What invades your body and defense when you catch a bug?

When you catch a bug, such as a virus or bacteria, these pathogens invade your body and begin to replicate, often triggering an immune response. Your immune system responds by deploying white blood cells, antibodies, and other defenses to identify and destroy the invaders. This process may lead to symptoms like fever and inflammation as your body works to fight off the infection. Ultimately, the goal is to eliminate the pathogens and restore your health.