New York - A new iPhone app allows migraine sufferers to keep a detailed diary of their symptoms and use of medication so they can have more effective conversations with their doctors. With the Migraine Notebook app patients can keep track of their day-to-day level of pain, the triggers that precede a migraine and when and at what dose they take their medicines. "One of the biggest issues in medicine is how you communicate with your doctor," said Dr Merle Diamond of the Diamond Headache Center in Chicago."This app gives us a window of communication which I think is really important in treating headaches. For example, it allows me to prepare questions about how they are using the medication," she said. About 30 million Americans, mostly women, suffer from migraines, according to the National Headache Foundation. Most commonly, it begins between the ages of 15 and 55 and in the majority of cases there is a family history. The headaches - which are characterised by a throbbing or pulsating pain, usually on one side of the head - can be accompanied by nausea or vomiting and sensitivity to light. Attacks can last from four to 72 hours or longer, according to the foundation. In a recent study of 1 218 migraine patients and 533 doctors, 91% of the physicians questioned said a migraine diary and medication tracker would help them in discussions with their patients. Seventy percent of patients who took part in the poll agreed. One-third of doctors also said it was difficult to evaluate how well treatment was working when patients could not describe their most recent attacks, according to the study conducted by the National Headache Foundation and healthcare company GlaxoSmithKline. "Migraines have a major impact on the quality of life of patients that suffer from them," Diamond said. "This allows us to become better self-advocates. We're going to need to be aggressive with our patients."