Headaches are common, and many people treat themselves with simple painkillers, drinking extra water or simply by waiting for the headache to go away. A headache is one of the most common reasons for attending a doctor's surgery or a neurology clinic.
What is a headache?
A headache is a pain or throbbing in the head or face. Almost everyone will experience headaches at some time. Most headaches are not caused by serious or sinister conditions.
People understandably worry if their headache symptoms seem different - either particularly severe, more frequent or unusual in any other way. The most common worry is that the headache is a symptom of a brain tumour.
This leaflet discusses headache generally. It explains the different types of headache experienced and describes those very rare situations where a headache can be a symptom of serious disease.
Types of headache
Headaches can be primary, or they can be secondary headaches which means they are a side-effect of a separate illness or injury.
Very occasionally, headaches need further investigation to rule out more serious underlying causes.
The most common types of headache, by a very long way, are tension headaches and migraines.
Types of headaches include:
Tension headaches are the most common type of headache and are usually felt as a band or pressure across the forehead. They can last for several days. They can be uncomfortable and tiring but they do not usually disturb sleep.
Most people can carry on working with a tension headache. They tend to worsen as the day progresses and are not usually made worse by physical activity, although it's not unusual to be a bit sensitive to bright light or noise. See the separate leaflet called Tension Headache.
Migraine headaches are also very common. A typical migraine is one-sided and throbbing, usually above or behind one eye. Headaches that are one-sided, headaches that cause throbbing pain and headaches that cause nausea are more likely to be migraines than anything else.
Migraines are often severe enough to be disabling. Some patients need to go to bed to sleep off their headache. They very often cause extreme sensitivity to light and sound. See the separate leaflet called Migraine.
Cluster headaches are very severe headaches, sometimes called 'suicide headaches'. They occur in clusters, often every day for a number of days or even weeks. They then disappear for months on end. They are uncommon and tend to occur particularly in adult male smokers.
They are one-sided headaches which are really very disabling (they prevent regular activity). People often describe them as the worst pain they have ever felt.
Patients often have a red watery eye on the affected side, a stuffy runny nose and a droopy eyelid. See the separate leaflet called Cluster Headaches.
Chronic tension headaches
Chronic tension headache (or chronic daily headache) is usually caused by muscle tension in the back of the neck and affects women more often than men. Chronic means that the condition is persistent and ongoing.
These headaches can be started by neck strain (for example, sitting awkwardly at a computer for hours per day) or tiredness and may be made worse by medication overuse (see below). When headaches occur almost every day for three months or more, this is called a chronic daily headache. See the separate leaflet called Chronic Tension Headache.
Medication-overuse headache (medication-induced headache or 'rebound headache') is an unpleasant and long-lasting headache. It is caused by taking painkilling medication - usually for headache.
Unfortunately, when painkillers are taken regularly for headaches, the body responds by making more pain sensors (in the nerve cells) in the head. Eventually there are so many pain sensors that the head is extremely sensitive and the headache won't go away.
People who have these headaches often take more and more painkillers to try to feel better. However, the painkillers have often long ceased to work.
Medication-overuse headaches are the most common cause of secondary headache. These headaches can be treated but require stopping of the painkillers which can be difficult in the short-term. Read more in the separate leaflet on Medication-overuse Headache (Medication-induced Headache).
Thunderclap headaches start very suddenly and are very painful. Pain reaches a maximum within about one minute; the headache lasts at least five minutes but sometimes much longer. It is important to seek medical attention immediately because thunderclap headaches are often caused by a serious underlying health condition, such as a subarachnoid haemorrhage.
Exertional headaches/sexual headaches
Exertional headaches are headaches associated with physical activity. They can become severe very quickly after a strenuous activity such as running, coughing, having sex (intercourse)or straining with bowel movements. They are more commonly experienced by patients who also have migraines or who have relatives with migraine.
Headaches related to sex particularly worry patients. They can occur as sex begins, at orgasm, or after sex is over. Headaches at orgasm are the most common type. They tend to be severe, at the back of the head, behind the eyes or all over. They last about twenty minutes and are not usually a sign of any other problems.
Exertional and sexual intercourse-related headaches are not usually a sign of serious underlying problems. Very occasionally they can be a sign that there is a leaky blood vessel on the surface of the brain so if they are marked and repeated, it is sensible to seek medical help.
Primary stabbing headaches
Primary stabbing headaches are sometimes called 'ice-pick headaches' or 'idiopathic stabbing headache'. The term 'idiopathic' is used by doctors for something that comes without a clear cause. These are short, stabbing headaches which are very sudden and severe. They usually last between 5 and 30 seconds, at any time of the day or night. They feel as if a sharp object (like an ice pick) is being stuck into the head.
They often occur in or just behind the ear and they can be quite frightening. Although they are not migraines they are more common in people who have migraines - almost half of people who experience migraines have primary stabbing headaches. They are often felt in the place on the head where the migraines tend to occur.
Primary stabbing headaches are too short to treat although migraine prevention medications may reduce their frequency.
Hemicrania continua is a primary chronic daily headache. It typically causes a continuous but fluctuating head pain on one side. The pain is usually continuous with episodes of more severe pain, which can last between 20 minutes and several days.
During these episodes of severe pain there may be other symptoms such as watering or redness of the eye, runny or blocked nose, and drooping of the eyelid, all on the same side as the headache. Similar to migraine, there may also be sensitivity to light, feeling sick (nausea) and being sick (vomiting).
The headaches do not go away on their own but there may be periods without the headache. However, hemicrania continua headaches respond well to a medicine called indometacin.
Trigeminal neuralgia causes facial pain. The pain consists of extremely short bursts of electric shock-like sensation in the face - in the area of the eyes, nose, scalp, forehead, jaws and/or lips. It is usually one-sided and is more common in people over the age of 50. It can be triggered by touch or a light breeze on the face but can come on without any trigger. See the separate leaflet called Trigeminal Neuralgia.
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What causes headaches?
Sometimes headaches have underlying causes and treatment of the headache involves treating the cause. People often worry that headaches are caused by serious disease or by high blood pressure. Both of these are very uncommon causes of headache; high blood pressure usually causes no symptoms at all.
Chemicals, drugs and substance withdrawal
Headaches can be due to a substance, or its withdrawal, Some examples are:
- Carbon monoxide (which is produced by gas heaters which are not properly ventilated).
- Drinking alcohol (with headache often experienced the morning after).
- Lack of body fluid (dehydration).
- Caffeine (people often develop headaches if they have reduced the amount of caffeine they drink; this resolves over a few days as the body gets used to the reduced caffeine).
Headaches due to referred pain
Some headaches can be caused by pain in some other part of the head, such as tooth, ear , jaw or neck.
Sinusitis is a common cause. The sinuses are 'holes' in the skull which are there to stop it from being too heavy for the neck to carry around. They are lined with mucous membranes, like the lining of the nose, and this produces mucus in response to colds or allergy. The lining membranes also swell up and may block the drainage of the mucus from the space. It then becomes thickened and infected, leading to headache.
The headache of sinusitis is often felt at the front of the head and also in the face or teeth. Often the face feels tender to pressure, particularly just below the eyes and beside the nose. There may be an associated stuffy nose and the pain is often worse on bending forwards. Acute sinusitis is the type that comes on quickly in association with a cold or sudden allergy. It is sometimes accompanied by a temperature and the production of a lot of mucus.
Chronic sinusitis can be caused by allergy, by overusing decongestants or by an acute sinusitis that doesn't settle. The sinuses become chronically infected and the sinus linings chronically swollen. The contents of the sinuses may be thick but often not infected.
Acute glaucoma can cause severe headache. In this condition the pressure inside one of the eyes goes up suddenly and this causes a sudden, very severe headache behind the eye. The eyeball can feel very hard to touch, the eye is red, the front of the eye (cornea) can look cloudy and the vision is usually blurred. The pupil often looks fixed and does not respond to light. This is a medical emergency and immediate medical attention should be sought.
How to get rid of a headache
There are a number of ways to try to prevent headaches or to help get rid of a headache. No one method works for everyone or every headache so it is sensible to experiment with different options.
- Drinking enough fluids but avoiding or limiting alcohol.
- Getting enough sleep and avoiding screen time (TV, computers, etc) before going to bed.
- Drinking a small amount of caffeine.
- Applying a cold pack to the eyes or head.
- Having a warm bath or shower.
- Staying in a darkened, quiet room.
- Trying methods to help relaxation, such as mindfulness, breathing exercises, lavender oil, meditation or yoga.
- Trying acupressure, acupuncture, massage, or osteopathic or chiropractic treatments.
- Taking simple pain relief, such as paracetamol, ibuprofen or aspirin. (Aspirin cannot be taken by children under the age of 18.)
What types of headaches are serious?
All headaches are unpleasant and some, such as headache from medication misuse, are serious in the sense that when not tackled properly they may be very difficult and troublesome to treat. However, a few headaches are signs of serious underlying problems. These are uncommon - in many cases very rare.
Dangerous headaches tend to occur suddenly, and to become progressively worse over time. They are more common in older people. They include the following:
Bleeding around the brain (subarachnoid haemorrhage)
Subarachnoid haemorrhage is a very serious condition which occurs when a small blood vessel bursts on the surface of the brain. People develop a severe headache and stiff neck and may become unconscious. This is a rare cause of severe headache.
Meningitis and brain infections
Meningitis is infection of the tissues around and on the surface of the brain and encephalitis is infection of the brain itself. Brain infections can be caused by germs called bacteria, viruses or fungi and they are thankfully rare. They can cause a severe, disabling headache.
Usually people are sick (vomit) and cannot bear bright light (this is called photophobia). Often they have a stiff neck, too stiff for the doctor to be able to bend the head down so that the chin touches the chest (even if trying to relax). People with meningitis or encephalitis are usually also unwell - hot, sweaty and ill.
Giant cell arteritis (temporal arteritis)
Giant cell arteritis (temporal arteritis) is usually only seen in people over the age of 50. It is caused by swelling (inflammation) of the arteries in the temples and behind the eye. It causes a headache behind the forehead (a frontal headache).
Typically the arteries in the forehead are tender and people notice pain in the scalp when they comb their hair. Often the pain gets worse with chewing. Temporal arteritis is serious because if it is not treated it can cause sudden loss of eyesight.
Treatment is with a course of steroids. The need to continue these steroids is usually monitored by the GP surgery and they are typically needed for many months.
Brain tumour is a very uncommon cause of headaches - although most patients with long-lasting, severe or persistent headaches start to worry that this may be the cause.
Usually the headache of brain tumours is present on waking in the morning, is worse on sitting up, and gets steadily worse from day to day, never easing and never disappearing. It can sometimes be worse on coughing and sneezing (as can sinus headaches and migraines).
When to worry about a headache
Most headaches don't have a serious underlying cause.
The things which would suggest to a clinician that a headache might need further investigation include the following. They do not mean that the headache is serious or sinister but they mean that the clinician might wish to do some further checks to be sure:
- There has been a significant head injury in the previous three months.
- The headaches are worsening and accompanied by high temperature (fever).
- The headache started extremely suddenly.
- Problems with speech and balance have developed along with the headache.
- There are problems with memory or changes in behaviour or personality as well as headache.
- The headaches are accompanied by confusion or feeling muddled.
- The headache started on coughing, sneezing or straining.
- The headache is worse when you sit or stand.
- The headache is associated with red or painful eyes.
- The headaches are not like anything experienced before.
- There is unexplained vomiting with the headache.
- There is reduced immunity - for example, if in someone with HIV, or who is on oral steroid medication or immune suppressing drugs.
- The person has or has had a cancer that can spread through the body.
How to prevent a headache
- Manage stress levels well.
- Eat a balanced, regular diet.
- Take balanced regular exercise.
- Pay attention to posture and core muscles.
- Sleep on two pillows or fewer.
- Drink plenty of water.
- Have plenty of sleep.
Any of these should improve health and well-being and reduce the number of headaches.
Most headaches, whilst unpleasant, are harmless and respond to simple measures. Migraine, tension headache and medication-overuse headache are all very common. Most of the population will experience one or more of these. Working out the underlying cause of any headaches is often the best way to solve them.
Most headaches go away by themselves. It is very rare for them to be a sign of a serious or sinister underlying condition.
Medical advice should be sought for a headache that is unusual or headaches which are particularly severe or stop regular activities, those which are associated with other symptoms like weakness or tingling, and those which cause a sore scalp (especially over 50 years of age).
Finally, seek medical attention for a morning headache which is present for several days, which does not go away or is getting gradually worse.
Further reading and references
Prakash S, Patel P; Hemicrania continua: clinical review, diagnosis and management. J Pain Res. 2017 Jun 2910:1493-1509. doi: 10.2147/JPR.S128472. eCollection 2017.
National Headache Management System for Adults 2019; British Association for the Study of Headache (2019)
Headache - assessment; NICE CKS, March 2022 (UK access only)
Headache - tension-type; NICE CKS, July 2022 (UK access only)
Headache - cluster; NICE CKS, April 2022 (UK access only)
Headache - medication overuse; NICE CKS, May 2022 (UK access only)