Hello
It sounds like there is a positional pressure issue that is occurring. My first question would be what is your mattress like? Ideally, the studies show that you should have a mattress that is moderately firm. You want enough support for your back. If the mattress is too soft, then it will not support your back and could be a potential cause of pain. The mattress does not need to be too firm though. If you want to add a pillow top or a thin tempurpedic type topper over the moderately firm mattress, that is usually ok.
Do you get this same pain if you lie down on a couch or another flat suraface? If not, then it points to some issue with your mattress. If you also have discomfort when lying on other surfaces, then it may be more of a positional issue with your spine. If you have more pressure on one side of your back, then this can get worse over time as you sleep during the night.
The best sleep position are on your back or side. When on your back you can put a small pillow or two under your knees if this is comfortable. You can also try sleeping on your left side. Keep you spine neutral and bend your hips and knees and finally put a pillow between your knees to keep the legs and back more balanced. You can also try this on the right side to see if that helps. When on your side, you can also try a small towel roll at your waist, which can further support the back in neutral. You should use enough pillow to keep the neck supported in neutral as well when you are sleeping. Sleeping on your stomach is not an ideal position, especially for the neck.
When turning, try to brace with your abdominal muscles and roll as a log when you do have to turn. When getting out of bed, roll onto one side and then push yourself up with your arms when on the side and let the legs go over the side of the bed. This is better for your back than getting out of bed by sitting straight up.
If the above-mentioned do not help your pain, then I would recommend seeing a DPT or MD for further asessment. They can determine the cause of the problem. It sounds like it could be musculoskeletal and therefore an evaluation by a professional would help you get to the bottom of the problem.
You can Find a PT at: www.moveforwardpt.com
Good luck.
Dr. Mary Ann Wilmarth