Pain of the lower back, also known as lumbago, is a common condition that causes discomfort and pain in the lower back region. It is usually caused by muscle strain or sprain, but can also be caused by other medical conditions such as arthritis or sciatica. Symptoms of lumbago include stiffness, soreness, and difficulty moving the affected area. Treatment for lumbago typically involves rest, physical therapy, and medications to reduce inflammation and pain.