Good day i sometimes hear a crackling sound when my head moves,but what causes that?

Arthritis: This usually represents some arthritis in the neck. The sound comes from the vertebrae not moving smoothly as you turn your head. or flex neck. It may not be present all the time and there does not have to be any pain involved. If you start to have pain and cracking see your doctor. It is important to set your car headrest so the neck cannot snap way back. Protect your neck from jerking movements.