red02,
Without an examination, it is not really possible to tell you what is going on.
In the absence of neurological problems (pain radiating into the lower extremities, numbness/tingling in specific areas of the lower extremities), the back pain is usually musculoskeletal in origin.
Weight management, core muscle strengthening, spine and lower extremeity flexibility, and cardiovascular fitness are the mainstays of management.
Other management methods are basically anything that helps with the discomfort, and these vary widely. Some patients find chiropractic manipulation or massage therapy to help extensively. Hot pack, hot tub, jacuzzi, hot shower all can help with tightness in the lower back muscles. Some patients find home traction helps (this usually helps more the the C-spine than for the lumbar region, but some patients say it helps). Other things include such methods as: TENS unit, accupuncture, biofeedback, relaxation techniques, counseling, spiritual groups, music therapy, aroma therapy, over the counter medicines, etc. Methods which need medical input: injections, surgery, prescription medicines.
However, if a dedicated therapy program does not eliminate the problem, or you develop neurological symptoms, you may want to see a spine specialist.
Good luck.