Bursitis happens when a bursa becomes inflamed and swollen. A bursa is a sac under the skin filled with fluid that covers the joints, cushioning it from the bones and tendons. With regards to the main bursitis signs, symptoms, and treatment, the symptoms include tenderness, swelling, and pain. These are easily treatable with over the counter painkillers. While it can happen in any joint, it is most common in the hip, knee (housemaid’s knee), elbow, and shoulder. However, it is also quite common in the Achilles tendon, the foot, and the ankle.