4. Cause: Bursitis

Bursae are fluid-filled sacs that surround the area where muscles, tendons, and skin meet. They work like grease for your joints and provide lubrication to your bones. Bursitis occurs when bursae become inflamed, causing pain and discomfort. Treatments for bursitis include resting, pain medication, antibiotics, corticosteroids, physical therapy, and sometimes surgery. After treatment, the symptoms may disappear, but bursitis can also become chronic.