Back pain causes 13 million working days to be lost in Britain each year.
The spine supports the whole weight of the upper body and therefore it is understandable that it sometimes goes wrong. Because of the complex nature of the spine it is advisable to consult your doctor if back pain persists for more than a few days.
If, as is usual, the pain has been caused by abuse i.e. lifting too heavy weights etc, be sensible and take things easy. Take care to sit as upright as possible with a support for the small of the back. Take aspirin or paracetamol, which will not only relieve the pain but will help to relieve the inflammation.