If you have injured your back by lifting, falling etc.
Rest.
Lie on a firm bed in a comfortable position on your back or side.
Minimise movement.
Don’t do stretches, exercises or get physiotherapy.
Don’t take painkillers.
Don’t see a surgeon until you have done the above for at least 1 month with no improvement.
Pain is the bodies way of encouraging rest.
The body can heal itself but it can only do this when it is not moving.
Imagine a mechanic trying to repair your car engine while it is running !
Please note that your doctor will probably tell you to do the opposite of the above.