If the back of the neck hurts when the head is lowered, the following causes are common: First, cervical spondylosis: it can cause continuous spasm and tension in the muscles behind the neck, and when the head is lowered, pulling the neck muscles will make the pain symptoms very obvious, and the patient will feel the clinical symptoms of stiffness at the back of the neck, and through taking X-rays and MRI, the cervical spine disease can be confirmed. Second, fallen pillow: a fallen pillow during sleep will also cause pain behind the neck when lowering the head, usually the pain is more intense and unbearable for the patient and can only be mildly relieved by resting in bed. Therefore, if the patient has pain behind the neck when lowering the head, must be early diagnosis and early treatment, in order to make the symptoms can be quickly relieved. Patients should usually pay attention to protect the cervical spine to avoid the above diseases and prevent the recurrence of symptoms.