Question: I'm 30 weeks pregnant and my back constantly hurts with a feeling of numbness. What is it?

Answer: It is common for pregnant mums to experience backaches. However if there is numbness as well, you could have a prolapsed intervertebral disc which is pressing onto a nerve causing the numbness.
Check with your doctor. You need to rest your back for a couple of weeks or more. Do not lift heavy things off the floor. Never bend over to pick things, always bend your knees and keep your back straight (that, of course, is almost impossible when you are this pregnant). You would want to clear this problem soon before the delivery, otherwise a vaginal delivery might be a problem for you.