There Are More Reasons For A Stiff Neck. A stiff neck can be due to many reasons. You can even treat most of them at home. But it is better never to ignore them. It is very annoying when you get a stiff neck. Not only this, it can even be an indication of tumor or some other serious infection. There can be many reasons for a stiff neck. A few of these can be whiplash or ergonomics. Wear and tear is another reason. Sleeping in a funny position is another reason for getting a stiff neck. It is not advisable to ignore a stiff neck. At times, it can even be the sign of something systemic. Generally, a stiff neck is not something to be alarmed about. Certain situations besides combined conditions may require medical attention. It is the levator scapula which causes the feeling of a stiff neck. This is the same muscle which provides the connection between the neck and the shoulder. Thus, headache may or may not accompany a stiff neck.