Have you wondered why you have head pain or suffer from headaches? Here are 3 reasons why your head may hurt. 1. Neck-related Headaches Neck-related headaches are caused by tight, knotted neck muscles and stiff joints at the upper C2 and C3 vertebral levels, that irritate nerves and blood vessels going to the head. Common causes are stress, poor posture, poor work ergonomics and whiplash injury. Physiotherapy is effective in relieving these headaches, using ultrasound, massag