Headache can be caused by many different conditions and must be carefully differentiated. Tension headaches and migraine headaches account for 90% of cases. These types of headaches are usually not life threatening and are caused by muscle contraction and/or vascular problems. Cervicogenic headache is a type of headache caused by neuromusculoskeletal dysfunctions in the neck. Other causes of headache include allergies, sinus problems, hormone imbalances, infection, tumours, and head injury.