The document presents the Chronic Migraine Severity Scale (CMSS), a new scale for measuring the severity and impact of chronic migraine. The CMSS ranges from 0-100 points, with higher scores indicating greater severity: 0-25 is mild, 26-50 is moderate, 51-75 is severe, and 76-100 is very severe. It measures four impact categories: headache frequency, productivity loss, analgesic use, and comorbidities like anxiety, mood, sleep quality and bodily pain. The CMSS is intended to be a useful clinical and research tool for evaluating chronic migraine severity and determining appropriate treatment strategies.