Having a headache on most days is more common than many people think. A 2022 review of population studies estimated that 4.6% of people worldwide have headache on 15 or more days a month. When this goes on for more than 3 months, doctors call it chronic.
The usual causes are chronic migraine, chronic tension-type headache, and headaches caused by taking painkillers too often. This last one is called medication overuse headache. The three often overlap. Caffeine and poor sleep can add to the picture.
Daily headaches are rarely a sign of something dangerous, but they are worth taking to a GP. They are treatable. A new headache that started suddenly, or comes with the warning signs below, needs checking urgently.
Get help now
Call 112 or 999 in Ireland, 999 in the UK or 911 in the US, or go to an emergency department, if you have a headache and:
Get an urgent GP appointment the same day (or NHS 111 in the UK) if:
See a GP soon if:
NICE, the guideline body for England, uses these definitions:
NICE says chronic migraine and chronic tension-type headache commonly overlap. If there are any migraine features, it says to diagnose chronic migraine.
Medication overuse headache can sit on top of either.
This is one of the most important causes to rule out. The International Headache Society classification (ICHD-3) says studies from many countries show the same thing. More than half of people with headache on 15 or more days a month have medication overuse headache.
NICE says to consider it if your headaches started or got worse while taking these for 3 months or more:
The HSE advises trying not to take the maximum dose of painkillers on more than 2 days a week. It says more than this could make headaches harder to treat. MedlinePlus advises talking to your doctor if you take pain medicines on 3 or more days a week.
ICHD-3 says medication overuse headache usually, but not always, settles once the overuse stops. NICE says it is treated by withdrawing the overused medicine. Some medicines, such as strong opioids, need specialist support to stop.
Do not stop a prescribed medicine on your own. Read more about how painkillers can cause headaches, and what treatment involves.
The NHS says migraine usually causes a throbbing headache, often on one side, that gets worse when you move. Feeling sick and sensitivity to light and sound are common.
In chronic migraine, the headaches become so frequent that separate attacks are hard to tell apart. ICHD-3 says the character of the headache may change from day to day. Some days feel like migraine and others like a tension headache.
ICHD-3 also says the most common cause of headaches that look like chronic migraine is medication overuse. Around half of people who seem to have chronic migraine go back to less frequent migraine after stopping the overused medicine.
If you are not sure which type you get, see how to tell migraine, tension-type and cluster headache apart.
ICHD-3 describes chronic tension-type headache as daily or very frequent headache. It usually develops from less frequent tension headaches. Its typical features are:
It may come with mild nausea, or sensitivity to light or sound. The NHS lists stress, sleep problems and caffeine among the common causes of tension headaches. If your headaches feel more like pressure, our guide to pressure in the head covers that in more detail.
Caffeine can cause headaches when you miss your usual amount. ICHD-3 describes caffeine withdrawal headache in people who have had more than 200 mg a day for more than 2 weeks. The headache starts within 24 hours of the last caffeine. It goes within 7 days of stopping caffeine completely.
The NHS suggests cutting down on drinks with caffeine, such as tea, coffee or cola, if you get tension headaches. If you cut down, a withdrawal headache for a few days is possible.
Poor sleep is on the NHS list of tension headache causes. The NHS also advises not sleeping more than usual when you have a headache, because it can make it worse.
Obstructive sleep apnoea is when breathing stops and starts during sleep. The NHS lists these symptoms:
ICHD-3 describes sleep apnoea headache as a morning headache, usually on both sides, lasting less than 4 hours. It goes with successful treatment of the sleep apnoea. ICHD-3 also notes that waking with a headache has many other possible causes. If these symptoms sound familiar, try the STOP-BANG sleep apnoea questions.
This headache is daily from the start. ICHD-3 says people can clearly remember the day it began, and it becomes constant within 24 hours. It is diagnosed once it has lasted more than 3 months.
It typically starts in people without a history of headaches. ICHD-3 describes two forms: one that clears up within several months without treatment, and one that is hard to treat. Doctors need to rule out other causes first, such as raised or low pressure around the brain.
The NHS says symptoms can last up to 2 weeks after a head injury, and advises a GP visit if they last longer. A headache after a head injury in the last 3 months is on the NHS emergency list above. Our article on concussion and current advice explains recovery.
Temporal arteritis (giant cell arteritis) is inflammation of the arteries, especially at the temples. The NHS lists frequent, severe headaches, tender temples or scalp, jaw pain while eating or talking, and vision problems. It needs an urgent GP appointment, because untreated it can lead to stroke and blindness.
Raised pressure around the brain can cause a constant, throbbing headache. The NHS says it may be worse in the morning, or when coughing or straining. Vision may go dark or "greyed out" for a few seconds. The NHS says it is rare, but it can affect your vision.
Brain tumours. The NHS lists headaches among brain tumour symptoms. It advises seeing a GP if a headache feels different from your usual type, or if headaches are getting worse. Doctors look for specific warning features, such as a change in pattern or new symptoms in the nervous system.
Your GP will ask what the headaches feel like, where the pain is, how long it lasts and how often it comes. They will ask about other symptoms, any change in pattern, and every medicine you take for headache.
A headache diary is the most useful thing you can bring. NICE suggests recording for at least 8 weeks:
MedlinePlus says the diagnosis is usually based on your history of symptoms.
Most people do not need a brain scan. NICE advises against scanning people with tension-type headache, migraine, cluster headache or medication overuse headache solely for reassurance. It recommends further tests or referral if warning features appear.
Treatment depends on the type of headache. These are options in NICE guidance. Your GP will discuss what suits you.
NICE advises against opioids for treating tension-type headache or migraine attacks. The HSE says GPs may prescribe topiramate or propranolol for migraine in Ireland.
The NHS suggests these steps for headaches:
For tension headaches, the NHS adds exercise, yoga or massage, better sleep habits and less caffeine. Alcohol, irregular meals, too little fluid, periods and the menopause are other common NHS-listed triggers.
It is common, but it is not something you have to put up with. About 4.6% of people worldwide have headache on 15 or more days a month. It is usually treatable once the type is clear, so see a GP.
Yes. Taking painkillers for headache very often can cause medication overuse headache. NICE uses 10 or more days a month for triptans, opioids and combination painkillers. For paracetamol, aspirin or anti-inflammatories, it uses 15 or more days a month.
There are several possible reasons. Sleep apnoea, caffeine withdrawal overnight and painkiller overuse are among them. Rarely, raised pressure around the brain causes headaches that are worse in the morning. A GP can help work out which applies.
Usually not, if your headaches fit a known pattern and there are no warning signs. NICE advises against scans solely for reassurance in these headaches. A GP will arrange tests if warning features are present.
This article is general information, not medical advice. It cannot diagnose the cause of your headaches. Talk to your GP or pharmacist about your own headaches, and before starting, stopping or changing any medicine.
Reviewed by: Proco Team
Last updated: November 2026