What Causes a Migraine?

Migraines are more than just bad headaches. They’re a neurological disorder affecting around 1 in 7 people worldwide. While the exact cause of migraines remains complex, research has identified multiple processes that work together to trigger an attack. Understanding these processes can help you recognize patterns, avoid triggers, and seek appropriate treatment.

How the Brain and Nerves Get Involved

Migraines begin in the brain and involve a cascade of events that lead to throbbing pain, sensitivity to light or sound, and sometimes nausea or visual changes.

1. Cortical Spreading Depression (CSD)

   • A wave of electrical activity travels across the outer layer of the brain (cortex).
   • This wave temporarily alters blood flow and nerve signals, often causing the visual “aura” some people experience.

2. Activation of the Trigeminal Nerve

   • The trigeminal nerve carries sensory information from your face and head to the brain.
   • During a migraine, this nerve becomes overactive and releases chemicals that inflame blood vessels and surrounding tissues.

3. Neurogenic Inflammation

   • When nerve endings in the blood vessel walls release inflammatory substances (like calcitonin gene-related peptide, or CGRP), vessels swell and send pain signals.
   • CGRP is a key player—blocking it is one effective treatment approach.

4. Central Sensitization

   • Repeated migraine attacks can “teach” your brain to overreact to pain signals.
   • Over time, normal activities or mild stimuli can trigger or worsen an attack.

Genetic and Hormonal Influences

• Family History
  • If one or both parents get migraines, your risk increases. Researchers have pinpointed genes that affect ion channels and neurotransmitter function.
• Hormones
  • Fluctuating estrogen levels—especially around menstruation, pregnancy, or menopause—can trigger attacks in many women.
• Sleep and Circadian Rhythms
  • Irregular sleep patterns or jet lag upset your body clock, making a migraine more likely.

Common Migraine Triggers

Everyone’s “trigger list” is unique, but some factors are frequently reported:

• Diet and Drinks
– Aged cheeses, cured meats, and foods with preservatives (e.g., nitrates, MSG)
– Skipping meals or fasting
– Alcohol—especially red wine or beer
– Excessive caffeine or caffeine withdrawal

• Stress and Emotions
– High stress, anxiety, or emotional roller-coasters
– Post-​stress letdown (the “weekend migraine”)

• Sensory Stimuli
– Bright or flickering lights, glare, screens
– Loud noises, strong smells (perfume, smoke)

• Environmental Changes
– Weather shifts (barometric pressure drops)
– High altitude or poor air quality

• Physical Factors
– Dehydration or overhydration
– Intense exercise or physical exertion

From Trigger to Full-Blown Attack

1. Lowered Threshold
   Triggers push your brain closer to a migraine threshold. With repeated attacks, that threshold drops, so smaller triggers can set one off.

2. Brainstem Involvement
   Areas that regulate pain, vision, mood, and nausea become overactive. You feel that throbbing, one-sided head pain.

3. Chemical Release
   CGRP and other neuropeptides leak out, dilating blood vessels and fueling inflammation.

4. Pain Signals
   You experience the hallmark symptoms: pulsing headache, nausea, light/sound sensitivity, and sometimes visual disturbances or numbness.

Managing and Preventing Migraines

While there’s no cure, many steps can reduce frequency and severity.

Lifestyle Adjustments

• Keep a consistent sleep schedule, aiming for 7–9 hours each night.
• Eat balanced meals at regular times—never skip breakfast.
• Stay hydrated: drink water throughout the day.
• Manage stress with mindfulness, yoga, or gentle exercise.

Identify and Avoid Triggers

• Keep a migraine diary: note food, sleep, weather, stress, and activity.
• Look for patterns and gradually eliminate or manage offenders.

Acute (Abortive) Treatments

• Over-the-counter pain relievers (ibuprofen, aspirin) can help early.
• Prescription medications: triptans, ditans, or gepants target key migraine pathways.
• Anti-nausea drugs if vomiting is a problem.

Preventive (Prophylactic) Treatments

• Daily medications if you have frequent or severe migraines:
  • Beta-blockers (e.g., propranolol)
  • Antidepressants (e.g., amitriptyline)
  • Antiseizure drugs (e.g., topiramate)
  • CGRP inhibitors (monoclonal antibodies or small molecules)

• Non-drug options: biofeedback, cognitive behavioral therapy, acupuncture.

When to Seek Help

Migraines can often be managed, but certain warning signs mean you should act fast:

• A sudden, “worst ever” headache
• Headache after head injury
• Fever, stiff neck, rash, confusion, or seizures
• Change in headache pattern in someone over 50

You might also consider doing a free, online symptom check for to get a quick sense of what’s going on.

Always speak to a doctor if you experience anything life-threatening or seriously concerning.

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Migraines involve a mix of genetic makeup, nerve sensitivities, and environmental or lifestyle triggers. By understanding how these pieces fit together, you can work with your healthcare provider to craft a plan that brings you relief. If you’re struggling, don’t hesitate to talk to your doctor—effective treatments are available, and no one should face migraines alone.