Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Overview of Headache

By

Stephen D. Silberstein

, MD, Sidney Kimmel Medical College at Thomas Jefferson University

Last full review/revision Jul 2021| Content last modified Jul 2021
Click here for the Professional Version
GET THE QUICK FACTS
Topic Resources

A headache is pain in any part of the head, including the scalp, upper neck, face, and interior of the head. Headaches are one of the most common reasons people visit a doctor.

Headaches interfere with the ability to work and do daily tasks. Some people have frequent headaches. Other people hardly ever have them.

Causes of Headache

Although headaches can be painful and distressing, they are rarely due to a serious condition. Headaches can be divided into two types:

  • Primary headaches: Not caused by another disorder

  • Secondary headaches: Caused by another disorder

Primary headache disorders include

Trigeminal autonomic cephalgias are rare.

Secondary headaches may result from disorders of the brain, eyes, nose, throat, sinuses, teeth, jaws, ears, or neck or from a bodywide (systemic) disorder.

Common causes

Less common causes

Less often, headaches are due to a less common primary headache disorder called cluster headache Cluster Headaches A cluster headache causes severe pain that is felt at the temple or around the eye on one side of the head and that lasts a relatively short time (usually 30 minutes to 1 hour). It is accompanied... read more or to one of the many secondary headache disorders (see table Some Causes and Features of Headaches Some Causes and Features of Headaches A headache is pain in any part of the head, including the scalp, upper neck, face, and interior of the head. Headaches are one of the most common reasons people visit a doctor. Headaches interfere... read more ). Some secondary headache disorders are serious, particularly those that involve the brain, such as meningitis Introduction to Meningitis Meningitis is inflammation of the layers of tissue that cover the brain and spinal cord (meninges) and of the fluid-filled space between the meninges (subarachnoid space). Meningitis can be... read more , a brain tumor Overview of Brain Tumors A brain tumor can be a noncancerous (benign) or cancerous (malignant) growth in the brain. It may originate in the brain or have spread (metastasized) to the brain from another part of the body... read more , or bleeding within the brain (intracerebral hemorrhage Intracerebral Hemorrhage An intracerebral hemorrhage is bleeding within the brain. Intracerebral hemorrhage usually results from chronic high blood pressure. The first symptom is often a severe headache. Diagnosis is... read more ).

Contrary to what most people think, eye strain and high blood pressure (except for extremely high blood pressure) do not typically cause headaches.

Evaluation of Headache

Doctors focus on the following:

  • Determining whether the headache has another cause (that is, whether it is a secondary headache)

  • Checking for symptoms suggesting that the headache is caused by a serious disorder

If no cause is identified, they focus on identifying which type of primary headache is present.

Warning signs

In people with headaches, certain characteristics are cause for concern:

When to see a doctor

People who have any warning sign should see a doctor immediately. The presence of a warning sign may suggest that the headaches may be caused by a serious disorder, as for the following:

If people with none of the above symptoms or characteristics start having headaches that are different from any they have had before or if their usual headaches become unusually severe, they should call their doctor. Depending on their other symptoms, the doctor may ask them to come for an evaluation.

What the doctor does

Doctors first ask questions about the person's symptoms and medical history. Doctors then do a physical examination. What they find during the history and physical examination often suggests a cause of the pain and tests that may need to be done (see table Some Causes and Features of Headaches Some Causes and Features of Headaches A headache is pain in any part of the head, including the scalp, upper neck, face, and interior of the head. Headaches are one of the most common reasons people visit a doctor. Headaches interfere... read more ).

Doctors ask about the characteristics of the headache:

  • How often it occurs

  • How long it lasts

  • Where the pain is

  • How severe is it

  • What the pain is like (for example, whether it is throbbing, dull, or like a knife)

  • Whether any symptoms accompany it

  • How long a sudden headache takes to reach its maximum intensity

  • What triggers the headache, what makes it worse, and what relieves it

Other questions may include

  • Whether people have had headaches before

  • Whether the headaches recur and, if so, when did they start and how often do they occur

  • Whether the current headache is the same or different from previous headaches

Doctors also ask about risk factors for headache. They include

  • Whether people take or have stopped taking certain drugs

  • Whether they have a disorder that may account for the headache

  • Whether they have family members with severe headaches

  • Whether they have had a recent head injury

  • Whether they have had a spinal tap recently

People can think about how to answer the above questions and write the answers down before they go to the doctor. Sometimes doctors ask people to fill out a headache questionnaire that covers most of the relevant questions. People may complete the questionnaire before their visit and bring the results with them. Having this information written down can save time and help guide the evaluation.

Testing

Most people do not need testing. However, if doctors suspect a serious disorder, tests are done. For some suspected disorders, tests are done as soon as possible. In other cases, testing can be done within one or more days.

Magnetic resonance imaging (MRI) and/or magnetic resonance angiography (which provides detailed images of blood vessels) or, if MRI is not available or contraindicated, computed tomography (CT) is done as soon as possible if people have

MRI is done within a day or so if people have conditions such as the following:

  • Cancer

  • A weakened immune system (due to a disorder such as AIDS or a drug)

MRI or CT (if MRI is not available or is contraindicated) is done within a few days if people have certain other characteristics, such as the following:

  • Headaches that begin after age 50

  • Weight loss

  • Double vision

  • A new headache that is worse when the person awakens in the morning or that awakens the person from sleep

  • An increase in the frequency, duration, or intensity of chronic headaches

Usually, doctors do CT or MRI before the spinal tap if they think that pressure within the skull may be increased—for example, by a mass (such as a tumor, an abscess, or a hematoma). A spinal tap can be dangerous if pressure within the skull is increased. When spinal fluid is removed and pressure within the skull is increased, parts of the brain may suddenly shift downward. If these parts are pressed through the small openings in the tissues that separate the brain into compartments, a life-threatening disorder called brain herniation Herniation: The Brain Under Pressure Head injuries that involve the brain are particularly concerning. Common causes of head injuries include falls, motor vehicle crashes, assaults, and mishaps during sports and recreational activities... read more results.

Other tests are done within hours or days, depending on the examination results and the causes that are suspected.

Table
icon

Treatment of Headache

Treatment of headache depends on the cause.

Essentials for Older People

If headaches begin after age 50, doctors usually assume they result from another disorder until proved otherwise. Many disorders that cause headaches, such as giant cell arteritis, brain tumors, and subdural hematomas (which may result from falls), are more common among older people.

Treatment of headaches may be limited in older people. Older people are more likely to have disorders that prevent them from taking some of the drugs used to treat migraines and cluster headaches (triptans and dihydroergotamine—see table Some Drugs Used to Treat Migraines Some Drugs Used to Treat Migraines A migraine headache is typically a pulsating or throbbing pain that ranges from moderate to severe. It can affect one or both sides of the head. It is often worsened by physical activity, light... read more ). These disorders include angina, coronary artery disease, and uncontrolled high blood pressure.

If older people need to take drugs to treat headaches that can make them feel drowsy, they must be monitored closely.

Key Points

Drugs Mentioned In This Article

Generic Name Select Brand Names
D.H.E. 45, MIGRANAL
TYLENOL
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
Others also read
Test your knowledge
Brain
The brain consists of the cerebrum, brain stem, and cerebellum. It requires constant nourishment provided by a continual flow of blood and oxygen from the heart. Approximately how much of the blood pumped by the heart goes to the brain?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP