A headache can be defined as pain that is felt in the head or upper neck. The kind of pain associated with a headache may be described as dull, sharp, constant, throbbing, mild or intense. The brain itself does not contain receptors for pain, therefore cannot feel pain. Instead, the pain associated with a headache is caused by the irritation or inflammation of a variety of tissues including:
Headaches are one of the most common health-related conditions. Most commonly experienced by people 20-50 years of age, they are usually caused by more than one contributing factor.
A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.
One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.
A cavity within bone or other bodily tissue. Often refers to the hollow cavities within the facial bones on either side of the nose that filter the air that is breathed in through the nose.
Headaches are broadly categorised as being either primary or secondary, depending on the cause.
Primary headaches are:
There are three main types of primary headaches: tension, migraine and cluster.
These are:
The exact cause of tension headaches is still to be clearly understood. One popular explanation is that they are caused by contractions of the muscles covering the skull. It is thought that when the muscles that cover the skull undergo stress, they spasm and cause pain.
Another explanation suggests that changes in the levels of chemical messengers in the brain may cause tension headaches. In particular, the changes in the levels of the serotonin and endorphin messengers have been identified as potentially contributing to the pain associated with tension headaches.
Other factors that may cause or contribute to tension headaches include:
These are:
There is often a family history in people who experience migraine headaches. Migraines are caused by multiple complex interactions, but primarily thought to be a malfunction in the nerves of the brain. For some people who experience migraine headaches, there may be certain triggers such as certain foods or beverages, hormonal changes, or stress.
These are:
Cluster headaches are thought to be caused by abnormalities in an area of the brain called the hypothalamus. The hypothalamus is where the body's biological clock is located. The cyclic nature of cluster headache attacks can be explained by the involvement of the hypothalamus. Once a cluster period has begun, alcohol can make the headache worse.
Secondary headaches are:
They may be due to:
A problematic physiological response to an allergen that comes into contact with the body.
A type of chemical messenger (neurotransmitter) that is produced by the brain in response to fear, emotion and pain.
A condition causing inflammation to the inside of some blood vessels, in particular the arteries of the head and neck.
A chemical substance secreted in one part of an organism and transported to another part of that organism, where it has a specific effect.
A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.
The sum of all chemical changes that take place within an organism to maintain growth and development and convert food into energy and building blocks.
One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.
A chemical messenger within the brain that is thought to play a role in mood and behaviour. Many antidepressant medications act by increasing the amount of serotonin in the brain.
Bleeding into a space between two of the membranes that surround the brain, the arachnoid and pia meninges. It is usually associated with an aneurysm or weakened blood vessel.
A growth caused by an abnormal and uncontrolled reproduction of cells.
Relating to hormones, which are chemicals secreted in one part of an organism and transported to another part of that organism, where they have a specific effect.
The risk factors for primary headaches may vary, depending on the type of headache experienced. Some typical risk factors for primary headaches may include:
The risk factors for secondary headaches depend on the underlying cause.
Tension headache symptoms may include:
Symptoms of migraine may include:
Migraine headaches can occur with or without aura. Migraine headaches without aura are more common.
Symptoms may include:
The locations of tension, migraine and cluster headaches.
The symptoms associated with a secondary headache may vary, depending on the underlying condition causing the headache.
Some secondary headaches may be associated with a more serious underlying condition and require prompt medical care. Some symptoms of secondary headaches that call for prompt medical care may include:
One cause of secondary headache, giant cell arteritis, is treated as a medical emergency and its symptoms may include:
An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.
A condition causing inflammation to the inside of some blood vessels, in particular the arteries of the head and neck.
Involuntary, abnormal contractions of muscles, leading to uncontrolled shakes and jerks of the body.
The slight indentations on each side of the head in front of the ears, at equal level with the eyes.
Diagnosing the cause of a headache may involve taking a detailed patient history, performing a physical examination and, when required, ordering diagnostic tests
While taking a patient history, some common questions that a doctor may ask may include:
To help determine the cause of a headache, the doctor may ask if any of the following symptoms accompany the headache:
If the history-taking indicates a primary headache, there may be no need to carry out further diagnostic testing and an appropriate treatment plan can be made. However, if the history-taking indicates an underlying condition, then further testing may be required.
Laboratory tests of the blood and urine can help determine whether other medical conditions such as diabetes, thyroid disorders (hyperthyroidism / hypothyroidism) or infection are the cause of the headache.
A lumbar puncture may be used to determine whether subarachnoid haemorrhage, meningitis or abnormal cerebrospinal fluid pressure is the cause of the headache.
A computerised tomography (CT) scan of the head may be used to determine if subarachnoid haemorrhage, a brain lesion, sinusitis or a related condition is the cause of the headache.
A magnetic resonance imaging (MRI) scan may be used to determine if a lesion, infection or abnormal build-up of fluid in the brain is the cause of the headache.
A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.
An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.
A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.
A sudden, involuntary contraction of muscle groups caused by abnormal electrical activity in the brain.
Bleeding into a space between two of the membranes that surround the brain, the arachnoid and pia meninges. It is usually associated with an aneurysm or weakened blood vessel.
The clear fluid that surrounds and protects the brain and the spinal cord.
A procedure that uses a needle to collect a sample of cerebrospinal fluid, which is the clear fluid surrounding the brain and spine, from the lower back (lumbar region) for analysis. It can also be performed to remove any excess fluid or to deliver medications.
Treatment of primary headaches may require a combined approach to factor in a number of triggers and causes. Some common treatments may include:
Migraine headaches may be treated with medications to ease the associated symptoms. Pain-relief medication used to treat migraine headaches may include:
Migraine headaches may be associated with symptoms other than pain. Treatment for these symptoms may include:
Some people may experience frequent migraines. Treatment for recurring migraine headaches may involve preventative medication such as:
It is important to take into account that all medications may be associated with side effects of varying severity.
Secondary headache
Depending on the cause, the treatment for a secondary headache may vary. Treatment may require further consultation with a medical specialist, such as a neurologist, optometrist or an ear, nose and throat (ENT) specialist to assess the underlying condition and establish an appropriate treatment plan.
Substances that hinder the activity of hormones such as adrenaline by blocking the beta receptors, found in many organs but particularly the heart and blood vessels. These are used to treat a range of conditions including high blood pressure and migraines.
One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.
A doctor who specialises in conditions of the nervous system.
Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.
A chemical messenger within the brain that is thought to play a role in mood and behaviour. Many antidepressant medications act by increasing the amount of serotonin in the brain.
The complications associated with primary headaches may vary according to their type, frequency and severity.
People who experience regular headaches may be more likely to also experience:
The complications associated with secondary headaches may vary widely according to their underlying condition.
A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.
By avoiding known triggers, a person can ease episodes of primary headaches. However, episodes of primary headaches can often persist and the type of headache may change, so that people may experience both tension headaches and migraine headaches. How often people experience episodes of headaches can vary widely; some people may experience headaches weekly, while for others it may be years between episodes.
A younger age of onset, such as during childhood, may be associated with an increased risk of experiencing headache as an adult.
The prognosis of secondary headaches may vary widely depending on the underlying condition causing the headaches. The nature of the underlying condition will influence the prognosis.
For people who experience primary headaches, reducing the frequency and/or severity of the headache episodes may be achieved by:
The prevention of secondary headaches may depend on the underlying condition causing the headaches.