Like oil in an engine
Healthy joint fluid is thick, like syrup. It is rich in hyaluronic acid. When you walk, it keeps the joint gliding smoothly. When you run or jump, it absorbs the impact.
With osteoarthritis, the body breaks down its own HA faster and makes less of it. The fluid turns thin and watery, so it can no longer cushion or protect the cartilage.
An HA injection (doctors call it viscosupplementation) puts that thick, protective fluid back where it’s needed. It can: