One of my friends have bad back pain from yesterday. and she's having a bit of a hard time breathing. she said it hurts lay on her back and sit down. what can cause this? and what can we do?

Please go to the doctor, urgent care or emergency room asap. The doctor will determine the cause & order the appropriate blood tests & x-rays. You can help the doctor by writing down everything you remember doing in the days prior; any trauma, medication, changes in routine. Breathing difficulty can be caused by many things & a physical medical evaluation is needed. Take care.

A variety of problems could cause this, such as vertebral fracture, or even kidney stone, and the breathing issues need to be addressed ASAP. Do not delay and see your doctor now.

Breathing difficulty warrants immediate attention. Take your friend to the ER of the nearest hospital.