Hi I have had pain in my right side of neck for about 4 weeks its worse pain I had can you tell me. What it can be please thank you?

Get medical examinat. Any pain that persists beyond 2-3 weeks has some reason other than a sprain etc and therefore requires medical evaluation by your doctor. After a physical exam he/she may order further tests to find the cause. Unless the pain starts going away on its own or with something simple like tylenol, (acetaminophen) you should seek medical attention from your doctor asap.