Yesterday, the left side of my neck went stiff while sleeping.now i can't move it at all. what do i do?

?torticolis: If you slept on your neck in an odd way, you may have a severe sprain, or a torticolis of your neck. Try an NSAID and warm compresses. If you have a high fever, feel really sick and have a sore stiff neck, go to the ed to make sure you do not have meningitis (which would be rare).

Neck pain treatment: Most neck pain is musculoskeletal (coming from the muscles). This is best treated with stretching, strengthening and careful attention to ergonomics (avoiding injury due to awkward positions and repetitive stress). Non-steroidal anti inflammatories (nsaids) can be beneficial as well. Ask your doctor about exercises for neck stretching and strengthening and other treatments.

Tight muscles?: Try applying moist heat for about 20 minutes at a time, and begin to mobilize the neck slowly while the heat is applied. A prescription muscle relaxer may be able to help you mobilize the neck faster over the next couple of days. If you begin to have symptoms in one of your arms, affected by neck motion, get checked out to see if you have a compressed nerve. An NSAID medicine may help as well.

Torticollis: If you are not sick but just have a stiff neck it could be a muscle spasm. Gentle heat, topical magnesium oil, and gentle massage may help it resolve over the next few days. Move your shoulders around. If persists or severe get a medical evaluation. See torticollis wikipedia.