What causes serious neck pain?

The best therapies for neck pain depend on its cause. Some of the more common causes of neck include:

•    muscle strain
•    osteoarthritis
•    rheumatoid arthritis or related conditions
•    minor injury
•    disc disease
For many of these, initial treatment may include heat, gentle stretching exercises balanced with rest, acetaminophen, and/or anti-inflammatory medicines (such as ibuprofen). Standard treatment for rheumatoid arthritis includes anti-inflammatory and immunosuppressive medicines.
Intermittent use of a neck brace and consultation with a physical therapist are often recommended for persistent neck pain. When a nerve is compressed (as may occur with disc disease), a cortisone injection may be helpful.  
If symptoms (such as fever or severe pain after an injury) suggest there may be a serious cause, prompt medical evaluation is warranted.