Tension headache is one of the most common forms of headaches and it can occur at any age. It is pain or discomfort in the head, scalp, or neck, usually associated with muscle tightness in these areas.Tension headache is one of the most common forms of headaches and it can occur at any age. It is pain or discomfort in the head, scalp, or neck, usually associated with muscle tightness in these areas.