what are some of the serious problems that causes severe back pain
Inflammation of the joints (arthritis) of the spine sometimes causes back pain. Osteoarthritis is the common form of arthritis and usually occurs in older people. Ankylosing spondylitis is another form of arthritis that can occur in young adults and which causes pain and stiffness in the lower back.
The pain in the leg or foot is often worse than the pain in the back. The irritation or pressure on the nerve may also cause pins and needles, numbness or weakness in part of a buttock, leg or foot. About 9 in 10 cases of nerve root back pain are due to a prolapsed disc - often called a slipped disc.