1. If you find that painkillers alone or combined adjuvant medications are not enough to fully resolve your problem, you may need preventive treatment if these characteristics are met: 2. An average of at least 2 headache attacks per month or headaches lasting more than 4 days over the last 3 months; 3. Painkillers alone are not effective or have more adverse effects, or your doctor does not think you are a good candidate for painkillers; 4. Taking painkillers at least 2 times a week or more; 5. Your doctor judges that you have a specific type of migraine; 6. The headache attacks are related to your menstrual cycle. With preventive treatment, you can reduce the frequency of migraine attacks, reduce the severity of attacks, reduce the adverse effects of migraine on your life, and also increase the effectiveness of painkillers.