Why We Get Headaches and Migraines, and What Really Stops Them

Almost everyone reading this has had a headache in the past year. Global surveys suggest more than half of all adults get at least one headache annually, and many get them every month. So the question of why we get headaches is not academic. It sits behind millions of lost work hours, ruined evenings, and a quiet pile of painkiller strips in the kitchen drawer. The good news is that the biology is now well mapped, and most of it points to a handful of fixable causes.

This guide walks through where head pain actually comes from, how to tell a tension headache from a migraine, the modern model of what a migraine really is, the triggers worth tracking, the treatments that hold up, and the warning signs that mean you stop reading and call a doctor.

Why we get headaches starts with one odd fact: the brain can’t feel its own pain

Here is the strange fact at the centre of the whole topic. Surgeons can operate on awake patients with the brain exposed, poking and cutting brain tissue, and the patient feels nothing from the brain itself. The brain has no pain receptors. So when your head hurts, the pain is never the brain crying out. It is coming from the structures around it.

Where head pain is born

The pain-sensitive parts of the head are the blood vessels in and around the skull, the meninges (the membranes covering the brain), the large nerves of the face and scalp, and the muscles of the neck, jaw, and scalp. The single most important of these is the trigeminal nerve, a large sensory nerve that supplies the face and much of the head. When its endings get irritated or its signalling goes haywire, you feel it as head pain. Cleveland Clinic describes this nerve as the main highway that carries most head-pain signals to the brain.

Why a tight neck becomes a headache

Sit hunched over a phone for an hour and the muscles at the base of your skull stay clenched the whole time. Those muscles refer pain upward and forward, which is why so many headaches feel like a band tightening around the forehead. The pain is real, but its source is muscular, not anything wrong inside the skull. This is the everyday mechanism behind the commonest headache of all.

The main types, and how to tell them apart

A big part of why we get headaches comes down to which kind you actually have. Doctors split headaches into two big groups. Primary headaches are the headache itself as the problem: tension-type, migraine, and cluster. Secondary headaches are a symptom of something else, like a sinus infection, dehydration, or caffeine withdrawal. Sorting yours into the right box is most of the battle, because the fixes differ.

Tension-type headache: the common one

This is the headache most people mean when they say “I have a headache.” The NHS lists it as the most common type. It feels like dull pressure or a tight band across the forehead or around the head, usually on both sides. It does not throb. It rarely makes you sick to your stomach, and normal light and movement do not make it much worse. Stress, tiredness, dehydration, eye strain, bad posture, and skipped meals are the usual culprits. Most cases ease with rest, water, and a simple painkiller.

Migraine: not just a strong headache

A migraine is a different beast. The pain is often throbbing or pulsing, frequently on one side of the head, and moderate to severe. It commonly comes with nausea, sometimes vomiting, and a strong dislike of light and sound, so sufferers retreat to a dark, quiet room. An attack can last from a few hours to three days. About a third of people get an aura first: visual zigzags, flashing lights, blind spots, or tingling that creeps up an arm, usually 20 to 60 minutes before the pain. Migraine is more common in women, and it tends to run in families.

Cluster headache: rare and brutal

Cluster headache is uncommon but unforgettable for those who get it. The pain is severe, strictly on one side, and centres around or behind one eye. That eye often goes red and watery and the nostril on the same side runs or blocks. Attacks are short, 15 minutes to a couple of hours, but they strike in clusters, several a day for weeks, often waking the person at the same time each night. It is sometimes called “suicide headache” for its intensity. It needs specialist treatment, not over-the-counter pills.

Secondary headaches: when the head pain is a messenger

Plenty of headaches are downstream of something else. Dehydration on a hot Punjab afternoon. A blocked sinus during a chest infection. The thumping head that arrives on day one of a fast or a coffee-free morning, which is caffeine withdrawal. And the sneaky one that this article keeps coming back to: a headache caused by the very painkillers taken to stop headaches.

The table below lays out the three primary types side by side so you can place your own pattern.

Feature	Tension-type	Migraine	Cluster
Pain quality	Dull, pressing band	Throbbing, pulsing	Severe, boring, stabbing
Location	Both sides	Often one side	Around one eye
Typical length	30 min to a few hours	4 hours to 3 days	15 min to 2 hours
Other symptoms	Few	Nausea, light and sound sensitivity, aura	Red watery eye, blocked nostril, restlessness
How common	Most common	Common	Rare

What a migraine really is now

For decades the textbook story was simple and wrong. Blood vessels in the head were said to first narrow (causing the aura) then swell (causing the pain), and that was that. The “vascular theory” shaped how migraine was explained for most of the twentieth century. It does not survive modern evidence.

From blood vessels to the brain itself

The current view treats migraine as a disorder of an overexcitable brain and its nerve pathways. The key player is the trigeminovascular system: the trigeminal nerve and the blood vessels it connects to. During an attack this system fires abnormally and releases inflammatory chemicals around the blood vessels of the meninges. The American Migraine Foundation explains that vessel changes are a consequence of this nerve activity, not the first cause.

CGRP: the molecule that rewrote the field

One chemical released during this process is CGRP (calcitonin gene-related peptide). Levels of it rise during a migraine attack, it widens blood vessels, and injecting it into people prone to migraine can set off an attack. That single thread of evidence turned into a whole class of medicines. Drugs that block CGRP or its receptor now prevent and treat migraine, and their success is the strongest proof yet that the trigeminovascular model is right.

Aura is a wave across the brain

The aura that some people see is not the eyes playing tricks. It reflects a slow wave of altered electrical activity sweeping across the surface of the brain, known as cortical spreading depression. As the wave passes over the vision centre at the back of the brain, the person sees the classic shimmering arc. The wave moves at a steady, slow pace, which fits why an aura grows and drifts over many minutes rather than flashing on all at once.

The triggers worth tracking

Migraines and many tension headaches have triggers, and they stack. One alone might do nothing; three together tip you over. The honest truth is that triggers are personal, so the only reliable way to find yours is a simple diary: date, what you ate, sleep, stress, and the headache that followed. Patterns show up within a few weeks.

The big, boring, common ones

Mayo Clinic and the NHS point to the same short list again and again. Skipped or late meals and the blood-sugar dip that follows. Not drinking enough water. Too little sleep, or too much, or a changed sleep schedule. Stress, and oddly the let-down after stress, which is why weekend migraines are a thing. Long hours of screen glare and squinting. These five account for a large share of everyday attacks.

Food, hormones, and weather

Some foods are repeat offenders for some people: aged cheese, processed and cured meats, monosodium glutamate, alcohol (red wine especially), and for a few, chocolate. None of these triggers everyone, which is why blanket “migraine diets” usually disappoint. Hormonal change is a major trigger in women, with many attacks clustering around the menstrual period as oestrogen drops. Weather swings and bright sunlight round out the list.

The Pakistani context

A few local realities matter. Long, hot summers make dehydration headaches routine, and they are easy to miss when you simply are not drinking enough through the day. Ramadan brings its own pattern: the first few days of fasting often produce headaches driven by caffeine withdrawal and missed water, which usually settle as the body adjusts. And chai is woven into the day here, so a sudden drop in tea intake can itself trigger a withdrawal headache.

What actually works

Treatment splits into two jobs: stopping an attack you already have, and preventing the next ones. Most people only ever need the first, plus some lifestyle housekeeping.

The unglamorous basics that prevent most headaches

Once you understand why we get headaches, the basics make obvious sense. Before any pill, the foundations do real work. Drink water steadily across the day. Keep meals regular so blood sugar does not crash. Protect sleep, going to bed and waking at roughly the same time, weekends included. Take screen breaks and check your posture. Manage stress with whatever genuinely lowers it for you, whether that is a walk, prayer, or proper rest. For people whose stress headaches link to long-term tension, our piece on cortisol and chronic stress explains why the body’s stress chemistry keeps muscles clenched. And because poor sleep is such a reliable trigger, it is worth understanding what happens to your body during sleep.

Painkillers, and the trap hidden inside them

For the occasional headache, simple analgesics work well: paracetamol, or anti-inflammatories like ibuprofen or aspirin. The catch is in the word “occasional.” Here is the part most people have never heard. Taking painkillers for headaches too often, more than about 10 to 15 days a month depending on the drug, can cause a medication-overuse headache: a near-daily, dull headache driven by the treatment itself. The NHS flags this as a common and badly under-recognised cause of chronic daily headache. The cure is awkward but simple: stop the offending painkiller, accept a rough week or two, and the pattern usually breaks. If you want the deeper story of how these drugs dull pain in the first place, read the science of pain and painkillers.

Migraine-specific treatment

When a simple painkiller is not enough for migraine, the next step is a triptan, a prescription drug that targets the serotonin pathways involved in an attack and works best taken early. Anti-nausea medicines help the sickness. For people with frequent or disabling migraine, prevention is the goal, and options now include older drugs (some blood-pressure and anti-seizure medicines, certain antidepressants) and the newer CGRP medicines, either monthly injections or daily tablets, designed specifically to head off attacks. These are a genuine advance for people who get many migraine days a month, and a doctor decides who they fit.

The table below pairs the common triggers with the fix that actually addresses each one.

Trigger	What it does	The fix that works
Skipped meals	Blood sugar dips and triggers an attack	Eat at regular times, do not skip breakfast
Dehydration	Common in heat and while fasting	Sip water across the day, more in summer
Poor or irregular sleep	Both too little and too much can trigger	Fixed sleep and wake times, weekends too
Stress and the post-stress let-down	Muscle tension and chemistry shifts	Regular wind-down, walks, managed workload
Caffeine withdrawal	Headache on cutting chai or coffee	Reduce gradually, keep intake steady
Painkiller overuse	Causes medication-overuse headache	Limit to a few days a month, see a doctor

Red-flag headaches that need urgent care

The overwhelming majority of headaches are harmless once you understand them. A small minority are not, and the difference can matter a great deal. The pattern to learn is “new and different.” A headache unlike any you have had before, especially one that arrives suddenly or comes with other neurological signs, is the one to take seriously.

The signs that mean call now

A thunderclap headache, peaking to maximum pain within seconds or a minute and often described as the worst ever, can signal bleeding around the brain and is a medical emergency. A headache with fever and a stiff neck, particularly with a rash or confusion, can mean meningitis. Any significant headache after a head injury, anything with sudden weakness, slurred speech, drooping face, or loss of vision, or a fit, needs emergency care. A brand-new type of headache appearing for the first time after age 50, or one that steadily worsens over days and weeks, or that is consistently worst in the morning, deserves prompt assessment. Johns Hopkins Medicine keeps a clear public list of these warning features.

When to see a doctor, not the emergency room. Short of emergencies, see your doctor if headaches are getting more frequent or more severe, if they are not controlled by simple painkillers, if you are reaching for painkillers most days, or if headaches are interfering with work, sleep, or daily life. These are all fixable problems, and most have good treatment once correctly labelled.

Frequently asked questions

Is the headache itself dangerous, or just painful?

For the vast majority of headaches, the answer is just painful. Tension headaches and migraines hurt and disrupt life, but they do not damage the brain. The pain comes from nerves, muscles, and vessels around the brain, not from injury to brain tissue. The rare dangerous headaches announce themselves differently: sudden, severe, or paired with fever, weakness, or confusion.

How do I know if it is a migraine or just a bad headache?

Look at the features, not the severity. A migraine usually throbs, often sits on one side, and brings nausea plus a strong dislike of light and sound, so you want a dark, quiet room. About a third of sufferers get a visual aura first. A tension headache is a steady, dull, pressing band on both sides without nausea, and light and movement do not make it much worse.

Can painkillers actually cause headaches?

Yes, and it is common. Taking painkillers for headache on more than roughly 10 to 15 days a month can trigger a medication-overuse headache, a dull near-daily headache driven by the treatment. The NHS lists it as a frequent cause of chronic daily headache. The fix is to stop the painkiller, ride out a rough week or two, and the daily pattern usually clears.

What is CGRP and why does it matter?

CGRP is a signalling molecule (calcitonin gene-related peptide) released during a migraine attack. It widens blood vessels and amplifies pain signalling, and giving it to migraine-prone people can set off an attack. Medicines that block CGRP now prevent and treat migraine, which is strong evidence that migraine is a nerve disorder rather than a simple blood-vessel problem.

Does dehydration really cause headaches?

For many people, yes. Not drinking enough, especially in hot weather or while fasting, is a well-recognised trigger. The headache often eases within an hour or two of rehydrating. In Pakistan’s summers and during Ramadan it is one of the most preventable causes of head pain, and the fix costs nothing.

When should a headache send me to the emergency room?

Go immediately for a sudden “worst ever” headache that peaks within seconds, a headache with fever and a stiff neck, any headache after a head injury, or one with weakness, slurred speech, vision loss, confusion, or a seizure. A first-ever severe headache after age 50, or a headache that steadily worsens over days, also needs prompt medical assessment.

Are the new migraine prevention drugs worth it?

For people with frequent or disabling migraine, the CGRP medicines (monthly injections or daily tablets) are a real advance and prevent attacks in many who failed older drugs. They are not first-line for someone with the odd headache, and a doctor decides who fits. For occasional headaches, the basics of water, sleep, and regular meals do most of the work.

Understanding why we get headaches turns most of them from a mystery into a checklist: drink, sleep, eat on time, ease the muscle tension, and use painkillers rarely.