- This condition affects 80 – 90% of people per year
- Most headaches are not a serious risk to health
- A mild headache can be easily treated by taking an aspirin or other simple painkiller, but their regular use can lead to serious problems
- Stress is one of the most common triggers for most types of headaches
- However, headaches may be a warning sign of more serious disorders
- In diagnosing and treating headaches, a multidisciplinary approach is essential
Almost everyone suffers from a headache from time to time. Most headaches are infrequent and transient annoyances that disappear with the help of an analgesic or other pain killer. But for one person in ten, a headache is an excruciating experience that might herald some serious disorder.
About 15% of the population have headaches severe or frequent enough to consult a doctor. In fact, headache is the most common cause of pain that prompts patients to consult their GP.
Even children get headaches, some well before the age of ten. Before puberty, headaches are more common in boys.
In adults, headaches are four times more prevalent in women and often linked to hormonal fluctuations. In both sexes the frequency and severity of headaches decline with advancing years.
What are the causes?
Headaches are broadly divided into two groups, primary and secondary.
- The most common type of primary headache is scalp and neck “muscle contraction” or tension headache. This affects 20% of the population. Tension headaches are primarily caused by abnormal tension in the muscles of the head and neck, which is often exacerbated by stress or anxiety.
- Migraine, which has an important vascular component, makes up the other large group of primary headaches – affecting 5 to 10% of the population.
- Cluster headaches are primary headaches that affect only about one percent of headache sufferers. They are important, though, because they are so severe – so severe in fact that they are often referred to as 'suicide headaches'.
- Tension headaches and vascular headaches such as migraine can occur in an individual at the same time. In fact, in practice, the distinction between these two entities is seldom clear-cut, and muscle tension and vascular pain almost always occur simultaneously to varying degrees.
Secondary headaches are those headaches caused by some other identifiable condition. With secondary headache, once the underlying medical condition has been identified and treated, the headache subsides. Examples of secondary headache are:
- Headaches due to infection of surrounding structures: sinus infection, tonsillitis, toothache, meningitis.
- Headache due to inflammation of surrounding tissues: cervical spine arthritis, constant coughing, straining of the eyes, acute glaucoma, trigeminal neuralgia (a neural disorder) and temporal arteritis (a disorder of the arteries).
- Certain conditions will cause a stretching or pulling of pain-sensitive parts and inner structures of the head. These include concussion and other head trauma, strokes, brain tumours and spinal taps (lumbar puncture).
If a headache is caused by a serious illness, other symptoms are often present, such as vomiting, dizziness or changes in vision.
Danger signs to be aware of may be:
- A 'first time' headache, or a headache that has changed in nature
- Headache brought on by exertion
- Headache accompanied by fever
- Headache accompanied by drowsiness or confusion
- Headache with stiff neck (especially if fever and nausea are also present)
- Headache accompanied by physical abnormalities, such as muscular weakness, sensory loss, tremor and gait disturbances.
- Headache in a patient who simply 'looks ill'
Although the above can be signs of a serious or life threatening problem, this is not always the case.
One of the main reasons why headaches are difficult to treat is that there is a bewildering array of triggers that can set off a headache. As a result, these triggers are often blamed for the headache, whereas in reality, the patient's body is reacting abnormally to the trigger. In other words, there is an underlying abnormal condition that makes the body react to the trigger. If the underlying abnormality is identified and treated, then very often the trigger no longer has the same effect.
Of course, if a trigger is identified, and can be easily avoided, then one should do so. This is particularly true of dietary triggers, over which the patient has the ultimate control. The problem comes in with triggers such as stress, which is a normal phenomenon that everyone has to some extent. It is in most cases impossible to avoid stress – most people can't change their lifestyle, job, relationships, etc. The same is true for hormonal triggers – most women with hormone-related migraines have normal hormone levels. However, their bodies are reacting abnormally to the normal cyclical changes in hormone levels.
Identifying triggers is further complicated by the fact that in most people, migraine attacks are not triggered by just one thing. They often have several migraine triggers. When these triggers occur on their own, they may not bring on an attack, but when they occur together, they result in a migraine.
Dietary triggers are numerous and varied, but the most common are (remember that often what affects one person is fine for another):
- peanuts and peanut butter
- caffeine in all products, not just coffee
- dairy products
- some beans (which includes peanut), as well as broad, lima, Italian, lentil, soy, peas
- dried meats
- pickled herrings
- canned soups and packet soup mixes
- chicken livers
- soya products as well as the bean itself
- sodium nitrate, which is used to preserve hot dogs, bacon and cured meats
- the preservative benzoic acid and its associated compounds
- MSG, common name for monosodium glutamate, a flavour enhancer. Eating foods (such as Chinese food) prepared with monosodium glutamate is often cited as a trigger. Interestingly, research has not confirmed that this is true. If it were true, then one would also expect a greater prevalence of headache in Chinese people. The incidence, however, is the same as in other populations.
- sourdough breads
- cheeses which have been aged, i.e. cheddar
- red wines, beer, champagne, vermouth
A number of metabolic, toxic or environmental triggers are:
- Certain medications
- Eating or drinking iced foods and fluids
- The use or withdrawal of alcohol (“hangover”), caffeine, or other analgesic drugs (Medication Overuse Headache)
- Breathing in smoke or fumes from chemicals
- Repeated exposure to nitrate compounds (found in heart medicine and dynamite; also used in a meat preservative; sodium nitrate – such as in hot-dogs and bacon)
- Exposure to materials containing chemical solvents (for example benzene, turpentine, spray adhesives, rubber cement and certain inks)
- Exposure to poisons such as insecticides, lead and carbon tetrachloride
- Use of drugs such as amphetamines
- High altitudes (above 4 500m)
- High blood sugar (hyperglycaemia)
- Low blood sugar (hypoglycaemia)
- Low calcium levels in the blood (hypocalcaemia)
- Kidney failure (uraemia)
How is it diagnosed?
The first stage of diagnosis is a thorough medical and neurological examination, to exclude the possibility of secondary headache. In diagnosing secondary headaches, the patient's history is all important. A careful physical examination will be done to check for clues to possible headache causes and also to check the nervous system. The exam can help determine whether further testing is needed.
Any abnormal results in the physical exam may suggest a possible underlying cause of headache. Abnormal results may include:
- Fever, which may indicate an infection such as sinusitis. Headache with fever, stiff neck, nausea and vomiting may indicate meningitis.
- Headache that began suddenly in a person who has not had headaches before, or a dramatic change in an established headache pattern.
- Headache that follows any form of physical exertion, such as exercise, sexual activity, coughing or bending. These types of headaches are usually not caused by a serious problem, but occasionally they can be related to an aneurysm (ballooning of the wall of one of the blood vessels in the brain).
- Abnormal speech, eye movements, walking, co-ordination or reflexes.
- Abnormal eye exam, which indicates there may be increased pressure inside the skull.
- High blood pressure.
- Other findings, such as arthritis, which may suggest autoimmune disease.
- Onset of headaches after the age of about 55 could indicate a condition called temporal arteritis, which may, amongst other things, cause blindness if not treated early.
Imaging tests, such as MRI, MRA or CT scan, may be needed if your doctor suspects there is an underlying organic cause such as an aneurysm or brain tumour (although these are fortunately quite rare). Your doctor may also order an imaging test if your headaches continue to get worse despite conventional treatment.
People with primary headache, such as tension-type, migraine or cluster headache will usually have a normal physical examination.
Once the neurological examination has been done (and in the vast majority of headache sufferers this examination reveals no abnormality), the next step is to ascertain from which anatomical structures the pain originates.
The ideal way to do this is to employ what is called a 'multidisciplinary' approach. There are so many different structures in the head and neck, all of which can be involved in the headache process, that no single clinician or specialist can have all the knowledge necessary to make a comprehensive assessment and diagnosis. For this reason, the expertise of different specialists who would normally treat headache patients in isolation, should be combined and integrated into a single more comprehensive body of knowledge. This enables the team to provide a co-ordinated treatment plan, so that all the contributing factors are addressed.
Keeping a headache diary may help to identify triggers, and is also useful for evaluating the effectiveness of treatment.
An initial and fundamentally important step in the management of headache is to differentiate those headaches that are the result of other, often serious, conditions ('secondary' headaches) from headaches that are not caused by an underlying disease process ('primary' headaches).
Although symptomatic treatment of pain is also necessary in secondary headaches, it is crucial to treat the underlying cause. In the case of a brain tumour, this may mean surgical excision or a shunt to reduce raised intracranial pressure; antibiotics for bacterial meningitis; and surgical drainage of an intracranial haemorrhage.
Primary headaches are the far larger group, and include tension, migraine, and cluster headaches. They can be treated in two ways – either with preventive treatment, or with rescue treatment once the pain starts. Prevention is of course far preferable, and can be achieved in most patients.
The Migraine Generator
In order to understand the treatment rationale for primary headaches, it is necessary to understand the pain-producing mechanism. Current theory recognises the presence of a centre in the brain from which the headaches are triggered. It is generally known as the 'migraine generator'.
In headache sufferers, the migraine generator is thought to be more sensitive than in non-headache sufferers. Because of this it discharges more easily, resulting in headache or migraine. Incoming sensory messages from the structures making up the head and neck terminate in the migraine generator. When there are sufficient incoming messages, the migraine generator fires, and causes a headache. There are broadly two ways to prevent the headaches. One is to reduce the sensitivity of the migraine centre with medication, and the other is to reduce the number of incoming impulses reaching the migraine generator.
There are two approaches to preventive treatment, one by reducing the sensitivity of the migraine generator by means of drugs, and the other by reducing the number of impulses reaching the migraine generator.
All drugs have side effects and this approach is only recommended if all else fails. In addition, the drugs used to prevent primary headaches are often not effective.
It is preferable to make every effort to diagnose where abnormally high numbers of impulses are coming from and why, and to treat the cause or causes. In most primary headache sufferers, it is possible to achieve effective prevention without the use of drugs.
The best way to get to the root of the problem is by a 'multidisciplinary' approach. There are so many different structures in the head and neck, all of which can be involved in the headache process, that no single specialist can have all the knowledge necessary to make a comprehensive assessment and diagnosis. For this reason, the expertise of different specialists who would normally treat headache patients in isolation, is combined and integrated into a single more comprehensive body of knowledge. This makes it possible to provide a co-ordinated treatment plan, so that all the contributing factors are addressed.
There are several common-sense courses of action that may well prevent headaches by removing the triggering factors: A change in lifestyle that reduces stress may be enough – although for the majority of people, changing one's lifestyle is in practice impossible.
Some sufferers notice that certain situations or habitual patterns of behaviour are likely to trigger headache. Avoiding certain trigger foods and chemical compounds (perfumes, smoke) may be helpful in the management of migraine. Getting regular exercise, avoiding excessive caffeine and alcohol, stopping smoking and ensuring adequate hydration may also be helpful in some individuals, and they also have all sorts of other benefits.
Drugs for headache are either prophylactic or symptomatic.
Prophylactic medications are taken daily and are directed towards preventing the headache from developing in the first place. They are not pain medications.
There are a wide variety of prophylactic medications. Tricyclic antidepressants, like amitryptyline, are frequently used, and can ease headache even in those patients not clinically depressed. Other medications include several of the anti-epileptic drugs and the calcium channel blockers. Beta-blockers, used to lower blood pressure in other patients, are effective in migraine.
Although prophylactic or preventive medications may sometimes be effective in certain headache or migraine sufferers, the results have generally not been encouraging. There is also the very real problem of side effects, which can be more unpleasant than the headaches. A large percentage of people who have been prescribed preventive medications, stop taking them either because they are not effective, or because of the unpleasant side effects. For these reasons, prophylactic medication should be reserved for those patients who have not responded to other preventive treatment options.
Symptomatic, abortive or rescue medication
One of the main problems with taking painkillers for headaches is that it often leads to Medication Overuse Headache (MOH). MOH is a problem that occurs in headache sufferers who have to take painkillers on a regular basis – the headaches become more frequent and more severe! Because of this, the patient increases the dosage and takes the drugs more often, and a vicious circle is set up, making the headaches worse and worse. This can happen with any of the painkillers, but is far more likely to occur when the medication contains more than one drug, and especially if it contains caffeine, ergotomine or codeine. When the three are combined in one pill, there is an even greater likelihood of MOH developing. It is important that you examine the box or insert of the medications you use, and check what they contain. And remember – MOH can occur with prescription or Over-The-Counter headache medication.
If you suffer from headaches, the answer is not to rely on medication or painkillers. The correct way to deal with the problem is to have a proper diagnosis of the causes of the headache. If the causes can be successfully treated, the headaches no longer occur, and it is no longer necessary to rely on potentially harmful 'rescue' medication.
If you have not been able to have the proper diagnosis and treatment yet, and are forced to use medication, then symptomatic or 'abortive' medications are the pain medications that should be used. These are drugs are designed to stop the headache once it has started.
Once a headache has taken hold, any of a wide selection of abortive medications are used. These include simple analgesics like paracetamol and aspirin, anti-inflammatories and muscle relaxants. Narcotic analgesics may be necessary for the most severe headaches, but they are best limited to one-off usage, and should not be prescribed longer-term, as they are habit-forming. Often a trial-and-error approach is necessary to match an individual patient with the most suitable medication.
Migraine is often associated with intense nausea, and an anti-emetic (a drug that treats nausea and vomiting) may bring a measure of relief. Medications that act on the calibre of blood vessels have an important place in migraine therapy – the ergot drugs of old have largely been replaced by the newer 'triptan' medications like sumatriptan, which has oral, subcutaneous and intranasal forms. Unusual primary headaches like cluster may respond to breathing oxygen.
It should be mentioned that all headache medications have side-effects, and so should be used judiciously.
(Reviewed by Dr Elliot Shevel, director: Headache Centre)
The information provided in this article was correct at the time of publishing. At Mediclinic we endeavour to provide our patients and readers with accurate and reliable information, which is why we continually review and update our content. However, due to the dynamic nature of clinical information and medicine, some information may from time to time become outdated prior to revision.