Headaches are common, and many people treat themselves with simple painkillers, drinking extra water, and having a rest, 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.
Almost everyone will experience headaches at some time. Most headaches are not caused by serious or sinister conditions. However, people understandably worry if headaches seem different (either particularly severe, particularly 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 you may experience and describes those very rare situations where a headache is, in fact, a symptom of serious disease.
Types of headache
Headaches can be primary, or they can be secondary which means they are a side-effect of a separate illness or injury.
Your doctor can generally tell the likely cause of your headache from talking to you and examining you. Once he or she has discovered the cause then you will be able to decide how to reduce or stop the headaches. This may involve taking medication only when you get the headaches, taking daily medication to prevent them or, sometimes, stopping medication you are already taking.
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.
Tension headaches are usually felt as a band or 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. Read more about tension headaches.
Migraines are also very common. A typical migraine is one-sided and throbbing. Indeed, headaches that are one-sided, headaches that throb and headaches that make you feel sick 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. 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. Then they disappear for months on end. They are uncommon and tend to occur particularly in adult male smokers. They are severe, one-sided headaches, which are really very disabling (they prevent regular activity). People often describe them as the worst pain they have ever felt.
Cluster headaches are usually one-sided. Patients often have a red watery eye on the affected side, a stuffy runny nose and a droopy eyelid. Read more about 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 injuries or tiredness and may be made worse by medication overuse (see below). A headache that occurs almost every day for three months or more is called a chronic daily headache. Read more about chronic tension headaches.
Medication overuse headache (medication-induced 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 head. Eventually the pain sensors are so many that the head is super-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. Read more about medication-overuse headaches.
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), and 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. Therefore, if they are marked and repeated, it is sensible to discuss them with your doctor.
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 your 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 number.
Hemicrania continua is a primary chronic daily headache. It typically causes a continuous but fluctuating pain on one side of your head. 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 but there may be periods when you don't have any headaches. However hemicrania continua headaches respond 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 light breeze on the face. See the separate leaflet called Trigeminal Neuralgia.
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 extremely uncommon causes of headache - indeed high blood pressure usually causes no symptoms at all.
Chemicals, drugs and substance withdrawal
Headaches can be due to a substance, or its withdrawal - for example:
- 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).
Headaches due to referred pain
Some headaches can be caused by pain in some other part of the head, such as tooth or ear pain, pain in the jaw joint and pains in the 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 your 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. You may have a stuffy nose and the pain is often worse when you bend forwards. Acute sinusitis is the type that comes on quickly in association with a cold or sudden allergy. You may have a temperature and be producing 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 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.
What types of headache are serious or dangerous?
All headaches are unpleasant and some, such as headache from medication misuse, are serious in the sense that when not tackled properly they may never go away. 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. Patients 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 cause a severe, disabling headache. Usually patients 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 you try to relax). Patients are usually also unwell - hot, sweaty and ill.
Giant cell arteritis (temporal arteritis)
Giant cell arteritis (temporal arteritis) is, generally, 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 patients 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 your GP through blood tests, 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. Brain tumours can cause headaches. 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 should I be worried about a headache?
Most headaches don't have a serious underlying cause. However, healthcare professionals are trained to ask you about the signs and symptoms that might suggest your headache needs further investigation, just to make sure it's nothing serious.
The things which would suggest to your doctor and nurse that your headache might need further investigation include the following. They do not mean that your headache is serious or sinister, but they mean that the doctor or nurse might wish to do some further checks to be sure:
- You have had a significant head injury in the previous three months.
- Your headaches are worsening and accompanied by high temperature (fever).
- Your headaches start extremely suddenly.
- You have developed problems with speech and balance as well as headache.
- You have developed problems with your memory or changes in your behaviour or personality as well as headache.
- You are confused or muddled with your headache.
- Your headache started when you coughed, sneezed or strained.
- Your headache is worse when you sit or stand.
- Your headache is associated with red or painful eyes.
- Your headaches are not like anything you have ever experienced before.
- You have unexplained vomiting with the headache.
- You have low immunity - for example, if you have HIV, or are on oral steroid medication or immune suppressing drugs.
- You have or have had a type of cancer that can spread through the body.
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 through discussion with your doctor is often the best way to solve them. It is possible to develop a persistent (chronic) and continuous headache through taking simple painkilling medicines which you took to get rid of your headache. Your doctor can support you through the process of stopping painkillers if this is the case.
Headaches are, very rarely, a sign of a serious or sinister underlying condition, and most headaches go away by themselves.
If you have a headache which is unusual for you then you should discuss it with your doctor. You should also talk to your doctor about headaches which are particularly severe or that stop your regular activities, those which are associated with other symptoms like weakness or tingling, and those which make your scalp sore (especially if you are over 50 years of age). Finally, always talk to your doctor if you have an unremitting morning headache which is present for more than three days or is getting gradually worse.
Remember that headaches are less likely to occur in those who:
- Manage their 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.
Anything that you can do to improve any of these areas of your life will improve your health and well-being and reduce the number of headaches you experience.
Further reading and references
; British Association for the Study of Headache (BASH) Guidelines, (2010 - reviewed 2014)
; European Federation of Neurological Societies (August 2009)
; European Federation of Neurological Societies (2010)
; NICE CKS, May 2013 (UK access only)
; NICE CKS, November 2012 (UK access only)
; NICE CKS, November 2012 (UK access only)
; Hemicrania continua: clinical review, diagnosis and management. J Pain Res. 2017 Jun 2910:1493-1509. doi: 10.2147/JPR.S128472. eCollection 2017.