Migraines happen when nerve pathways in your brain become overly activated, triggering a cascade of chemical signals that produce intense, throbbing head pain. More than 39 million people in the U.S. live with migraine, and the condition is three times more common in women than men. The reasons you’re getting them likely involve a combination of your genetics, your hormones, your environment, and your daily habits.
What’s Happening in Your Brain
Migraine isn’t just a bad headache. It’s a neurological event. The process starts with a network of nerve fibers called the trigeminovascular system, which connects your brainstem to the blood vessels and membranes surrounding your brain. When this system becomes activated, it releases powerful signaling molecules that dilate blood vessels and trigger inflammation around the brain’s outer covering. One of the most important of these molecules, called CGRP, was identified nearly 40 years ago and has since become the primary target for newer migraine medications.
If you experience aura before your migraines (visual disturbances, tingling, or temporary difficulty speaking), that’s caused by a slow wave of electrical activity sweeping across the surface of your brain. During this wave, brain activity becomes dramatically suppressed for hours. This process essentially short-circuits normal brain function in one region before the pain phase kicks in.
Genetics Play a Significant Role
If your parents or siblings get migraines, your risk goes up substantially. Heritability is estimated at 38% for men and 48% for women, meaning roughly half of a woman’s migraine risk can be traced back to family. If you have a first-degree relative with migraine with aura, you’re nearly four times more likely to experience the same type. Even for migraine without aura, having a close relative with the condition almost doubles your risk.
The severity matters too. Relatives of people with disabling migraines are about twice as likely to develop migraines themselves, compared to only a modest increase in risk among relatives of people with mild attacks. Genetics alone don’t seal the deal, though. Familial factors account for less than half of all migraine cases, which means environment and lifestyle tip the balance for most people.
Hormones Are a Major Driver for Women
Estrogen is the key hormone. It’s not high or low estrogen that causes migraines, but the drop. The decline in estrogen just before your period is one of the most reliable migraine triggers, which is why many women notice attacks clustering around menstruation. Steady estrogen levels tend to improve headaches, while any rapid fluctuation can set one off.
This explains several patterns women notice throughout their lives. Migraines often improve during pregnancy, when estrogen levels are consistently high, but can return after delivery when estrogen plummets. During perimenopause, when hormone levels rise and fall unpredictably, migraines frequently become more frequent and severe. Migraine peaks between ages 35 and 45, which overlaps directly with the years of greatest hormonal fluctuation.
Common Triggers You Can Control
Most people with migraine have identifiable triggers, though they vary from person to person. The main categories worth tracking:
- Sleep disruption. Research from the University of Arizona found that poor or insufficient sleep significantly increases the likelihood of a migraine attack. Disrupted sleep appears to lower the threshold for triggering an episode. Limiting screen time before bed and keeping a consistent sleep schedule are among the simplest preventive steps you can take.
- Food and drink. Tyramine, a compound that builds up naturally as protein-rich foods age, is a well-known trigger. Aged cheeses, cured meats, and fermented foods are the main sources. Processed meats containing nitrates and nitrites are another common culprit. Large amounts of MSG can also provoke attacks. Everyone’s sensitivity is different, so a food diary is the most practical way to identify your personal triggers.
- Weather changes. Shifts in barometric pressure, bright sunlight, extreme heat or cold, high humidity, and stormy weather all appear on the list of triggers. These changes may cause imbalances in serotonin, one of the brain chemicals involved in migraine signaling. Weather triggers are harder to avoid, but knowing they affect you can help you prepare.
- Stress. Both the stress itself and the “letdown” period afterward (like the first day of a vacation) can trigger attacks.
Triggers tend to be cumulative. You might tolerate one trigger on its own but get a migraine when two or three stack up on the same day. A glass of wine might be fine when you’re well-rested but devastating after a night of poor sleep.
The Anxiety and Depression Connection
If you’ve noticed that your migraines seem worse during periods of anxiety or depression, the link is well documented. People with chronic headaches are about five times more likely to have symptoms of depression and seven times more likely to have symptoms of anxiety compared to people without headaches. Nearly half of adults with chronic headaches experience depression or anxiety alongside their head pain.
This relationship runs in both directions. Anxiety and depression can lower your pain threshold and increase how frequently migraines strike, while living with chronic migraines can fuel mood disorders. Addressing mental health often improves migraine frequency, and treating migraines can improve mood. If your attacks have become more frequent alongside changes in your emotional well-being, both issues are worth addressing together.
When Your Headache Pattern Should Concern You
Most migraines, while painful and disruptive, are not dangerous. But certain headache features signal something more serious. Headache specialists use a checklist of red flags to distinguish migraine from secondary headaches caused by other conditions:
- Sudden, explosive onset. A headache that reaches maximum intensity within seconds, sometimes called a thunderclap headache, can indicate a vascular emergency like an aneurysm. This is the single most concerning feature.
- New neurological symptoms. Weakness in an arm or leg, unusual numbness, or visual changes that are different from your typical aura pattern.
- Systemic symptoms. Fever, night sweats, or unexplained weight loss alongside headaches.
- New headaches after age 50. A first-time headache disorder appearing later in life is more likely to have a secondary cause.
- Clear progression. Headaches that are steadily becoming more severe or more frequent over weeks or months, rather than following a stable pattern.
- Positional changes. Pain that dramatically shifts when you stand up, lie down, or strain (coughing, bearing down).
- New headaches during or after pregnancy. These warrant evaluation for vascular or pituitary conditions.
If your migraines follow a recognizable, recurring pattern and respond to treatment, that’s reassuring. If anything about the pattern changes, especially suddenly, that’s the signal to get evaluated.
Putting It Together
For most people, migraines result from a genetically sensitive brain reacting to a combination of triggers. You inherited a nervous system that’s more reactive to certain stimuli, whether that’s hormonal shifts, sleep disruption, dietary compounds, or weather changes. The trigeminovascular system fires more easily than it does in someone without migraine, releasing inflammatory signals that produce pain.
The most effective approach is identifying which triggers matter most for you. Keep a migraine diary tracking your sleep, food, stress, menstrual cycle, and weather for two to three months. Patterns almost always emerge. Reducing your trigger load, even when you can’t eliminate every trigger, often reduces how many migraines you get. Newer preventive treatments that block CGRP signaling have been available since 2018 and represent a significant option for people whose migraines don’t respond well to lifestyle changes or older medications.