What is a headache?

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:

  • Meninges (coverings of the brain);
  • Periosteum (membranes covering the bones);
  • Muscles that encase the skull;
  • Sinuses;
  • Nerves and/or blood vessels, and;
  • Eyes and/or ears. 

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.

Inflammation

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.

Nerves

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Sinuses

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.

Causes

Headaches are broadly categorised as being either primary or secondary, depending on the cause.

Primary headaches

Primary headaches are:

  • Not due to an underlying condition;
  • Usually not dangerous, and;
  • Usually recurrent.

There are three main types of primary headaches: tension, migraine and cluster.

Tension headaches

These are:

  • The most common type of primary headache;
  • Usually mild and short-lived, and;
  • Either episodic or chronic. If they occur fewer than 15 days per month, they are episodic. If they occur more than 15 days per month, they are chronic.

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:

  • Depression;
  • Poor posture;
  • Stress;
  • Sleep disturbances;
  • Clenching of jaw muscles, and;
  • Grinding of teeth.

Migraine headaches

These are:

  • Less common than tension headaches;
  • Usually more severe and debilitating, and;
  • Longer-lasting - up to 72 hours.

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.

Cluster headaches

These are:

  • The least common type of primary headache;
  • Recurring - they generally occur at the same time each day, and;
  • Severe and debilitating, come in groups and may be separated by lengthy pain-free periods. 

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

Secondary headaches are:

  • Due to another underlying condition, and;
  • Either benign (cause no serious harm) or dangerous.

They may be due to:

Allergic reaction

A problematic physiological response to an allergen that comes into contact with the body.

Endorphin

A type of chemical messenger (neurotransmitter) that is produced by the brain in response to fear, emotion and pain.

Giant cell arteritis

A condition causing inflammation to the inside of some blood vessels, in particular the arteries of the head and neck.

Hormones

A chemical substance secreted in one part of an organism and transported to another part of that organism, where it has a specific effect.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Inflammation

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.

Metabolism

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.

Nerves

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Serotonin

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.

Subarachnoid haemorrhage

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.

Tumour

A growth caused by an abnormal and uncontrolled reproduction of cells.

Hormonal

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.

Risk factors

Primary headaches

The risk factors for primary headaches may vary, depending on the type of headache experienced. Some typical risk factors for primary headaches may include:

  • Smoking;
  • Excessive alcohol consumption;
  • A family history of headaches;
  • Being female;
  • Being an adult between 20-50 years of age, and;
  • Stress.

Secondary headaches

The risk factors for secondary headaches depend on the underlying cause.

Signs and symptoms

Tension headaches

Tension headache symptoms may include:

  • Pain that can be described as a dull ache, with constant pressure as if someone has placed a tight rubber band around the head;
  • Muscle tightness in the head, neck or jaw;
  • Mild sensitivity to light or noise, and;
  • Irritability.

Migraine headaches

Symptoms of migraine may include:

  • Moderate to severe pain that is often described as throbbing or pounding;
  • Pain that can affect the whole head, one side of the head, or can shift from one side to the other;
  • Pain that is aggravated by movement;
  • Nausea and vomiting;
  • Sensitivity to light and noise;
  • Blurred vision, and;
  • Bright flashing dots or lights, or blind spots (aura).

Migraine headaches can occur with or without aura. Migraine headaches without aura are more common.

Cluster headaches

Symptoms may include:

  • Severe and intense pain that is described as throbbing or constant;
  • Pain that is located behind one eye, or in the region of one eye and doesn't change locations during that episode;
  • Pain that lasts a short time, which can disappear only to come back later that day, and;
  • Runny eyes or nose on the same side of the face as the headache.

Where headache is felt; tension headache; migraine headache; types of headaches.The locations of tension, migraine and cluster headaches. 

Secondary 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:

  • A sudden and severe onset of headache associated with a stiff neck;
  • Headaches associated with a fever;
  • Convulsions;
  • Headaches associated with confusion or a loss of consciousness;
  • Persistent headaches in someone who was previously headache-free, and;
  • Recurring headaches in children.

One cause of secondary headache, giant cell arteritis, is treated as a medical emergency and its symptoms may include:

  • Persistent and severe headache, usually over the temple area;
  • Jaw pain with eating;
  • Blurred or double vision;
  • Scalp tenderness, fever, and;
  • Unexplained weight loss.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Giant cell arteritis

A condition causing inflammation to the inside of some blood vessels, in particular the arteries of the head and neck.

Convulsions

Involuntary, abnormal contractions of muscles, leading to uncontrolled shakes and jerks of the body.

Temple

The slight indentations on each side of the head in front of the ears, at equal level with the eyes.

Methods for diagnosis

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:

  • What does the headache feel like?
  • When does the headache occur?
  • How long does it last?
  • Where is the pain felt?
  • When did it begin?
  • Is this the worst headache of your life?
  • Is this the same as headaches you have had before?
  • What makes it worse?

To help determine the cause of a headache, the doctor may ask if any of the following symptoms accompany the headache:

  • Fever;
  • Vomiting;
  • Visual disturbances;
  • Seizures;
  • Confusion;
  • Dizziness;
  • Weakness or impaired movement, and;
  • Eye pain.

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.

Diagnostic testing

Blood tests and urinalysis

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.

Lumbar puncture

A lumbar puncture may be used to determine whether subarachnoid haemorrhage, meningitis or abnormal cerebrospinal fluid pressure is the cause of the headache.

Computerised tomography

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.

Magnetic resonance imaging

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.

Computerised tomography

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.

Diabetes

A metabolic disorder that is caused by problems with insulin secretion and regulation and which is characterised by high blood sugar levels. Also known as diabetes mellitus.

Fever

An increase in body temperature above the normal temperature range. Fever is often caused by the body's immune reaction to infection.

Infection

Entry into the body of microorganisms that can reproduce and cause disease.

Lesion

Damage to bodily tissue.

Magnetic resonance imaging

A type of imaging that uses a magnetic field and low-energy radio waves, instead of X-rays, to obtain images of organs.

Seizures

A sudden, involuntary contraction of muscle groups caused by abnormal electrical activity in the brain.

Subarachnoid haemorrhage

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.

Cerebrospinal fluid

The clear fluid that surrounds and protects the brain and the spinal cord.

Lumbar puncture

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.

Types of treatment

Primary headache

Treatment of primary headaches may require a combined approach to factor in a number of triggers and causes. Some common treatments may include:

  • Pain-relief medications, such as paracetamol or ibuprofen;
  • Avoiding known triggers, such as certain foods or drinks (especially caffeinated and alcoholic drinks);
  • Getting enough sleep;
  • Stress management;
  • Making changes to any medications that may be causing the headache as a side effect;
  • Treating the underlying condition causing the headache, and;
  • Exercise.

Migraine headaches

Migraine headaches may be treated with medications to ease the associated symptoms. Pain-relief medication used to treat migraine headaches may include:

  • Paracetamol;
  • Non-steroidal anti-inflammatory drugs (NSAIDs); 
  • Aspirin, and;
  • Triptans, which act on serotonin receptors in the nerves and blood vessels and decrease the release of the molecule associated with pain in the brain.

Migraine headaches may be associated with symptoms other than pain. Treatment for these symptoms may include:

  • Antiemetic medication (to treat nausea and vomiting), and;
  • Hydration.

Some people may experience frequent migraines. Treatment for recurring migraine headaches may involve preventative medication such as:

  • Beta-blockers including propranolol and metoprolol;
  • Serotonin antagonists including pizotifen;
  • Calcium-channel blockers;
  • Antiepileptic medications including topiramate, and;
  • Ergot derivatives including methysergide.

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.

Beta-blockers

Substances that hinder the activity of hormones such as adrenaline by blocking the beta receptors, found in many organs but particuarly the heart and blood vessels. These are used to treat a range of conditions including high blood pressure and migraines.

Nerves

One or more fibres that transmit signals of sensation and motion between the brain or spinal cord and other parts of the body.

Neurologist

A doctor who specialises in conditions of the nervous system.

NSAIDs

Non-steroidal anti-inflammatory drugs are commonly used to manage arthritis-related pain and inflammation and other musculoskeletal disorders. NSAIDs include aspirin and ibuprofen.

Optometrist

A health professional trained to detect eye conditions and prescribe glasses.

Serotonin

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.

Calcium-channel blockers

Also called a calcium antagonist. A group of medications that is used to treat high blood pressure and other conditions. It works by blocking calcium from entering cells of the heart and blood vessels, which ultimately lowers blood pressure.

Potential complications

Primary headache

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:

Secondary headache

The complications associated with secondary headaches may vary widely according to their underlying condition.

Anxiety

A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.

Prognosis

Primary headaches

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.

Secondary headaches

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.

Prevention

Primary headaches

For people who experience primary headaches, reducing the frequency and/or severity of the headache episodes may be achieved by:

  • Avoiding known triggers such as certain foods or beverages;
  • Maintaining good posture to ease muscle tension;
  • Eating a healthy diet;
  • Maintaining good stress management;
  • Avoiding drinking too much alcohol;
  • Eating regular meals;
  • Quitting smoking;
  • Avoiding eye strain, and;
  • Staying well hydrated.

Secondary headaches

The prevention of secondary headaches may depend on the underlying condition causing the headaches.