Your immune system is built to help you. And usually, it does. When an injury or infection damages cells in your body, immune cells and proteins rush to the site to draw attention to the problem and improve your condition. This is the process of inflammation.
Ideally, the surge of inflammatory cell activity tapers off when cellular repair begins. “That’s if everything goes according to plan,” says Keenan Walker, a neurologist at Johns Hopkins University School of Medicine. When inflammation doesn’t go as planned — like when it continues at low levels for a long time — that can cause more harm than good.