Your neck is flexible and supports the weight of your head, so it can be vulnerable to injuries and conditions that cause pain and restrict motion. Neck pain causes include: 1  Muscle strains. 2  Overuse, such as too many hours hunched over your computer or smartphone, often triggers muscle strains. Osteoarthritis causes the cushions (cartilage) between your bones (vertebrae) to deteriorate. 2  Your body then forms bone spurs that affect joint motion and cause pain. 3  Nerve compression. 4  Herniated disks or bone spurs in the vertebrae of your neck can press on the nerves branching out from the spinal cord.