If you don’t suffer from migraines yourself, odds are that you know someone who does. I myself need only to take a drive on a sunny day and watch the sunlight flash through the leafy trees to trigger a headache that feels like a vice being tightened around my head. I’m certain that the 36 million Americans who cope with these blinding headaches would be thrilled to find a way to stop the pain before it starts.

That’s why I was so interested to hear about a new study that takes a look at possible preemptive strategies against migraines based on the tiniest warning signals — signals that actually have nothing to do with head pain. Scientists are learning that these early alerts may precede the start of migraines by several hours to several days. Peter Goadsby, MD, PhD, director of the headache program at University of California, San Francisco, Headache Center, told attendees at the recent American Headache Society conference that these signals, which come about during a premonitory — or warning — phase of a migraine, also may hold clues as to why the headaches occur. Dr. Goadsby was someone I knew I wanted to talk to.

“What’s reasonably clear is that many patients experience a common pool of symptoms during the premonitory phase,” he told me. “That can mean neck discomfort, unusual tiredness, yawning, changes in appetite, excessive urinating or thirst, craving something sweet or savory, or mood changes, such as feeling unusually cranky or anxious.” In fact, he said, “It’s all pretty primitive symptomatology from a brain perspective.” And it’s there if you know what to look for!

Dr. Goadsby told me that in a study that he and colleagues published in Neurology, 97 migraine sufferers recorded their nonheadache symptoms on electronic diaries for three months and noted when migraines struck. Patients were able to correctly predict the onset of full-blown headaches from premonitory symptoms in 72% of diary entries. The most common of these symptoms were fatigue (experienced by 72%), difficulty concentrating (51%) and stiff neck (50%). Yawning, which occurred in about one-quarter of the headache sufferers, was a whopping 96% predictive of migraines.

The following is the complete list of premonitory symptoms reported in the study: Feeling tired or weary, dizziness, lots of energy or hyperactivity, excessive yawning, face paler than usual, stiff neck, light sensitivity, noise sensitivity, blurred vision, sensitive skin, constipation, frequent urination, nausea/vomiting, unusual hunger or food cravings, excessive thirst, feeling intolerant or irritable, feeling unusually emotional, difficulty with thinking, difficulty with reading or writing, difficulty with speech, difficulty with concentration.

So what’s different in all of this from the more familiar symptoms of migraine — known as the aura stage, which includes seeing flashing lights or wavy lines? For one thing, the warning signs studied by Dr. Goadsby tend to show up a lot earlier — in some cases, three days before the headache pain. Even more interesting is how the chicken-and-egg question is being turned on its head with this research. Until now, doctors and patients have focused on identifying behaviors that they assume play a role in triggering migraine — eating chocolate, for example. With the new research, it seems that the urge to eat chocolate actually could mean that the attack has already started, with the sign being a craving for sweets.

Current research is concentrating on using functional imaging of the brain to reveal which regions are involved in migraines and how they interplay with symptoms.

Already, however, the latest findings give migraine sufferers something new to try, says Dr. Goadsby. Every migraine sufferer knows that interrupting the pain early can cut the headache short. Now, by taking medicines such as naproxen or ibuprofen at the first sign of a premonitory symptom, they may be able to reduce or even prevent the pain.

Lifestyle adjustments may help as well. Avoiding a noisy party, bright lights or too much red wine, for instance, once you experience an early symptom could be a very wise move indeed.

“Generally, if you recognize the symptoms, a good strategy is to pull back from typical triggers when you feel them,” Dr. Goadsby says. “To not stay up late, not skip a meal, not push the envelope when the envelope is already pretty thin. Keeping a step ahead of triggering a migraine means practicing regularity in all things.”