Bursae are small, fluid-filled sacs located throughout the body, primarily near joints. They act as cushions, reducing friction between bones, tendons, and muscles during movement. This helps to prevent irritation and injury, allowing for smoother motion in areas like the shoulder, elbow, and knee. When bursae become inflamed, a condition known as bursitis can occur, leading to pain and swelling. Common causes of bursitis include repetitive movements, injury, or prolonged pressure on a joint. Treatment often involves rest, ice, and anti-inflammatory medications to relieve discomfort and restore normal function to the affected area.