A stiff neck can last from a few days up to a week, according to Spine-health.com. A stiff neck can be mild or severe. If caused by a traumatic injury or if accompanied by fever or other symptoms, prompt medical attention is recommended.
A stiff neck involves soreness or difficulty moving the neck, notes Spine-health.com. Headache, arm pain, neck pain or shoulder pain many occur concurrently with a stiff neck, or the individual may have to turn the whole body instead of just the neck when trying to move. A muscle sprain or strain on the muscle, cervical spine disorders, meningitis or other infections can cause a stiff neck.