I had pain on the left hand side of my back one day, then had it on the opposite side the next, then on shoulder blades. What can cause this?

Moving pain can be due to a slight interruption to blood supply.

This can be caused by sitting at a chair or in a car for prolonged periods at even a very slight angle.

Can you support your back with something soft?

Hopefully you have a few days off and the discomfort will recede.

If you feel you need a remedy to help, try some Valerian or Magnesium.

The valerian can help reduce muscle pain and aid sleep if that is affected.

Magnesium helps relax tense muscles.

Either should reduce any anxiety you feel that may exacerbate the problem.

Best wishes

Earle