Neck tightness and swelling are more causes in daily life, and the more common ones in clinical practice are neck muscle injury and cervical spondylosis, which are the two causes of neck muscle injury. 1. If you have recently lowered or tilted your head for a long time, the muscles of the neck will be fatigued and damaged due to prolonged contraction. The neck will feel tight and swollen, but at this time it is not usually accompanied by pain, and there is no radioactive pain and numbness in the arm; 2. Cervical spondylosis. If there is a long time low head and head tilt in daily life and work, in addition to neck tension and swelling, there is also radioactive pain and numbness in the arm, consider the possibility of cervical spondylosis, but the diagnosis still needs to go to the orthopedic department of the hospital for examination.