- Obstructive sleep apnea/snoring: This condition can cause dangerous narrowing or blockage of the airway—and sleeping on your back only makes it worse. One trick: sew a tennis ball to the back of your shirt so you have to roll over.
- Heartburn: Sleeping on your back is a no-no again. This condition is caused by gastric contents rising up the esophagus or back of the throat; counteract it by raising your head with pillows or heightening the head of your bed with bricks.
- Back pain: Flat on your back is often best—not bending forward by sinking into a soft mattress, or flexing forward under a pillow.
- Shoulder pain: Don't sleep on the side of the aching shoulder, obviously. Stay on your back with a little pillow under the sore shoulder, or on your other side and hug a pillow.
Click for more—including the best position for neck pain.