Headache

The headache pain may be a dull ache, sharp, throbbing, constant, intermittent, mild, or intense.

Headache is defined as pain arising from the head or upper neck of the body. The pain originates from the tissues and structures that surround the skull or the brain because the brain itself has no nerves that give rise to the sensation of pain (pain fibers). The thin layer of tissue (periosteum) that surrounds bones, muscles that encase the skull, sinuses, eyes, and ears, as well as thin tissues that cover the surface of the brain and spinal cord (meninges), arteries, veins, and nerves, all can become inflamed or irritated and cause a headache. The pain may be a dull ache, sharp, throbbing, constant, intermittent, mild, or intense.

In 2013, the International Headache Society released its latest classification system for headache. Because so many people suffer from headaches, and because treatment is difficult sometimes, the Headache Society hoped that the new classification system would help health care professionals make a more specific diagnosis as to the type of headache a patient has, and allow better and more effective options for treatment.

The guidelines are extensive, and the Headache Society recommends that health care professionals consult the guidelines frequently to make certain of the diagnosis.

There are three major categories of headache based upon the source of the pain.

1. Primary headaches
2. Secondary headaches
3. Cranial neuralgias, facial pain, and other headaches

The guidelines also note that a patient may have symptoms that are consistent with more than one type of headache, and that more than one type of headache may be present at the same time.

Migraine headaches are the second most common type of primary headache.

Primary headaches include migraine, tension, and cluster headaches, as well as a variety of other less common types of headaches.

• Tension headaches are the most common type of primary headache. Tension headaches occur more commonly among women than men. According to the World Health Organization, 1 in 20 people in the developed world suffer with a daily tension headache.
• Migraine headaches are the second most common type of primary headache. Migraine headaches affect children as well as adults. Before puberty, boys and girls are affected equally by migraine headaches, but after puberty, more women than men are affected.
• Cluster headaches are a rare type of primary headache. It more commonly affects men in their late 20s, though women and children can also suffer from this type of headache.

Primary headaches can affect the quality of life. Some people have occasional headaches that resolve quickly while others are debilitating. While these headaches are not life-threatening, they may be associated with symptoms that can mimic strokes.

Many patients equate severe headache with migraine, but the amount of pain does not determine the diagnosis of migraine. Read our Migraine Headache article for more information about the symptoms, causes, and treatment of migraines.

Secondary headaches are those that are due to an underlying structural or infectious problem in the head or neck. This is a very broad group of medical conditions ranging from dental pain from infected teeth or pain from an infected sinus, to life-threatening conditions like bleeding in the brain or infections like encephalitis or meningitis.

Traumatic headaches fall into this category including post-concussion headaches.

This group of headaches also includes those headaches associated with substance abuse and excess use of medications used to treat headaches (medication overuse headaches). "Hangover" headaches fall into this category as well. People who drink too much alcohol may waken with a well-established headache due to the effects of alcohol and dehydration.

Neuralgia means nerve pain (neur=nerve + algia=pain). Cranial neuralgia describes inflammation of one of the 12 cranial nerves coming from the brain that control the muscles and carry sensory signals (such as pain) to and from the head and neck. Perhaps the most commonly recognized example is trigeminal neuralgia, which affects cranial nerve V (the trigeminal nerve), the sensory nerve that supplies the face and can cause intense facial pain when irritated or inflamed.

The different types of headaches depend upon the class to which they belong. Some common types include:

1. Primary tension headaches that are episodic
2. Primary tension headaches that are chromic
3. Primary muscle contraction headaches
4. Primary migraine headaches with aura
5. Primary migraine headaches without aura
6. Primary cluster headache
7. Primary paroxysmal hemicrania (a type of cluster headache)
8. Primary cough headache
9. Primary stabbing headache
10. Primary headache associated with sexual intercourse
11. Primary thunderclap headache
12. Hypnic headache (headaches that awaken a person from sleep)
13. Hemicrania continua (headaches that are persistently on one side only, right or left [unilateral])
14. New daily-persistent headache (NDPH) (a type of chronic headache)
15. Headache from exertion
16. Trigeminal neuralgia and other cranial nerve inflammation
17. Secondary headaches due to:
    • Trauma
    • Disorders
    • Infection
    • Structural problems with the bones of the face, teeth, eyes, ears, nose, sinuses or other structures
    • Substance abuse or withdrawal

Migraine headache is caused by inflammation or irritation of structures that surround the brain or affect its function. While the brain itself has no pain nerve fibers, everything else above the shoulders, from the neck, skull, and face, can cause a person to have head pain. Systemic illnesses, including infection or dehydration, can have associated headache. These are known as toxic headache. Changes in circulation and blood flow or trauma can also cause headache.

Changes in brain chemistry may also be associated with headache: Medication reactions, drug abuse and drug withdrawal can all cause pain.

Every person is different so the history of the headache is important. Recognizing patterns or precipitating (foods eaten, stress, etc.) factors, in combination with the physical examination and associated symptoms, can help identify the cause for each individual's specific headache.

While tension headaches are the most frequently occurring type of headache, their cause is not known. The most likely cause is contraction of the muscles that cover the skull. When the muscles covering the skull are stressed, they may become inflamed, go into spasm, and cause pain. Common sites include the base of the skull where the trapezius muscles of the neck insert, the temples where muscles that move the jaw are located, and the forehead.

There is little research to confirm the exact cause of tension headaches. Some believe that tension headaches occur because of physical stress on the muscles of the head. For example, these stressors can cause the muscles surrounding the skull to clench the teeth and go into spasm. Physical stressors include difficult and prolonged manual labor, or sitting at a desk or computer concentrating for long periods. Emotional stress also might cause tension headaches by causing the muscles surrounding the skull to contract.

Common signs and symptoms of tension headaches include:

• Pain that begins in the back of the head and upper neck and is often described as a band-like tightness or pressure. It may spread to encircle the head.
• The most intense pressure may be felt at the temples or over the eyebrows where the temporalis and frontal muscles are located.
• The pain may vary in intensity but usually is not disabling, meaning that the sufferer may continue with daily activities. The pain usually is bilateral (affecting both sides of the head).
• The pain is not associated with an aura (see below), nausea, vomiting, or sensitivity to light and sound.
• The pain occurs sporadically (infrequently and without a pattern) but can occur frequently and even daily in some people.
• The pain allows most people to function normally, despite the headache.

The key to making the diagnosis of any headache is the history given by the patient. The health care professional will ask questions about the headache to try to help make the diagnosis. Those questions will try to define the quality, quantity, and duration of the pain, as well as any associated symptoms. The person with a tension headache will usually complain of mild-to-moderate pain that is located on both sides of the head. People with tension headaches describe the pain as a non-throbbing tightness, that is not made worse with activity. There usually are no associated symptoms like nausea, vomiting, or light sensitivity.

The physical examination, particularly the neurologic portion of the examination, is important in tension headaches because to make the diagnosis, it should be normal. However, there may be some tenderness of the scalp or neck muscles. If the health care professional finds an abnormality on neurologic exam, then the diagnosis of tension headache should be put on hold until the potential for other causes of headaches has been investigated.

Tension headaches are painful, and patients may be upset that the diagnosis is "only" a tension headache. Even though it is not life threatening, a tension headache can make daily activities more difficult to accomplish. Most people successfully treat themselves with over-the-counter (OTC) pain medications to control tension headaches. The following work well for most people:

• aspirin,
• ibuprofen (Motrin, Advil),
• acetaminophen (Tylenol, Panadol) and
• naproxen (Aleve).

If these fail, other supportive treatments are available. Recurrent headaches should be a signal to seek medical help. Physical therapy, massage, biofeedback, and stress management can all be used as adjuncts to help control tension headaches.

It is important to remember that OTC medications, while safe, are medications and may have side effects and potential interactions with prescription medications. It always is wise to ask a health care professional or pharmacist if one has questions about OTC medications and their use. This is especially important with OTC pain medications, because they are used so frequently.

It is important to read the listing of ingredients in OTC pain medications. Often an OTC medication is a combination of ingredients, and the second or third listed ingredient may have the potential of interfering with the action of other drugs based upon a patient's other medical issues. For example:

• Some OTC medications include caffeine, which may trigger rapid heartbeats in some patients.
• In nighttime preparations, diphenhydramine (Benadryl) may be added. This may cause sedation, and driving or using heavy machinery may not be appropriate when taking a sedative medication.
• Some OTC cold medications have pseudoephedrine mixed in with the pain medication. This drug can cause elevated blood pressure and palpitations.

Other examples where caution should be used include the following:

• Aspirin should not be used in children and teenagers because of the risk of Reye's syndrome, a life threatening complication that may occur when a viral infection is present and aspirin is taken.
• Aspirin, ibuprofen, and naproxen are anti-inflammatory medications that can be irritating to the stomach and may cause intestinal bleeding. They should be used with caution in patients who have peptic ulcer disease.
• Most anti-inflammatory medicines also cause the potential for bleeding elsewhere in the body, and you should not take them if you also take blood thinners. Talk with your doctor or other health care professional about the benefits and risks of anti-inflamatory drugs. Blood thinners include warfarin (Coumadin), heparin (Lovenox), dabigatran (Pradaxa), apixaban (Eliquis), rivaroxaban (Xarelto), edoxaban (Savaysa), clopidogrel bisulfate (Plavix), ticagrelor (Brilinta), and prasugrel (Effient).
• Overuse of aspirin, ibuprofen, and naproxen also may cause kidney damage.
• Acetaminophen, if used in amounts greater than recommended, can cause liver damage or failure. It also should be used with caution in patients who drink significant amounts of alcohol or who have liver disease because even lesser doses than are normally recommended may be dangerous.
• Medication overuse headache can be mistaken for chronic tension headaches. When pain medications are used for a prolonged period, headaches may recur because the effects of the medication wear off. (This type of headache was referred to as a "rebound headache," and is classified as a secondary headache.)

Cluster headaches are so named because they tend to occur daily for periods of a week or more followed by long periods of time -- months to years -- with no headaches. They occur at the same time of day, often waking the patient in the middle of the night.

The cause of cluster headaches is uncertain but may be due to a sudden release of the chemicals histamine and serotonin in the brain. The hypothalamus, an area located at the base of the brain, is responsible for the body's biologic clock and may be the source for this type of headache. When brain scans are performed on patients who are in the midst of a cluster headache, abnormal activity has been found in the hypothalamus.

Cluster headaches also:

• tend to run in families and this suggests that there may be a role for genetics;
• may be triggered by changes in sleep patterns; and
• may be triggered by medications (for example, nitroglycerin, used for heart disease)

If an individual is in a susceptible period for cluster headache, cigarette smoking, alcohol, and some foods (for example, chocolate, and foods high in nitrites like smoked meats) also are potential causes for headache.

Cluster headaches are headaches that come in groups (clusters) separated by pain-free periods of months or years. A patient may experience a headache on a daily basis for weeks or months and then be pain-free for years. This type of headache affects men more frequently. They often begin in adolescence but can extend into middle age.

• During the period in which the cluster headaches occur, pain typically occurs once or twice daily, but some patients may experience pain more than twice daily.
• Each episode of pain lasts from 30 to 90 minutes.
• Attacks tend to occur at about the same time every day and often awaken the patient at night from a sound sleep.
• The pain typically is excruciating and located around or behind one eye.
• Some patients describe the pain as feeling like a hot poker in the eye. The affected eye may become red, inflamed, and watery.
• The nose on the affected side may become congested and runny.

Unlike people with migraine headaches, those with cluster headaches tend to be restless. They often pace the floor and/or bang their heads against a wall. People with cluster headaches can be driven to desperate measures, including suicidal thoughts.

The diagnosis of cluster headache is made by taking the patient's history. The description of the pain and its clock-like recurrence is usually enough to make the diagnosis.

If examined in the midst of an attack, the patient usually is in a painful crisis and may have the eye and nose watering as described previously. If the patient is seen when the pain is not present, the physical examination is normal and the diagnosis will depend upon the history.

Cluster headaches may be very difficult to treat, and it may take trial and error to find the specific treatment regimen that will work for each patient. Since the headache recurs daily, there are two treatment needs. The pain of the first episode needs to be controlled, and the headaches that follow need to be prevented.

Initial treatment options may include one or more of the following:

• inhalation of high concentrations of oxygen (though this will not work if the headache is well established);
• injection of triptan medications, like, sumatriptan (Imitrex), zolmitriptan (Zomig), and rizatriptan (Maxalt) which are common migraine medications;
• spraying or dripping lidocaine, a local anesthetic, into the nostril;
• dihydroergotamine (DHE, Migranal), a medication that causes blood vessels to constrict; and
• caffeine.

Prevention of the next cluster headache may include

• calcium channel blockers, for example, verapamil (Calan, Verelan, Verelan PM, Isoptin, Covera-HS) and diltiazem (Cardizem, Dilacor, Tiazac);
• prednisone (Deltasone, Liquid Pred);
• antidepressant medications;
• lithium (Eskalith, Lithobid); and
• antiseizure medications including valproic acid, divalproex (Depakote, Depakote ER, Depakene, Depacon), and topiramate (Topamax).

Since cluster headache episodes may be spaced years apart, and since the first headache of a new cluster episode can't be predicted, daily medication may not be warranted.

Lifestyle changes may help minimize the risk of a cluster headache flare. Stopping smoking and minimizing alcohol may prevent future episodes of cluster headache.

Headache is a symptom associated with many illnesses. While head pain itself is the issue with primary headaches, secondary headaches are due to an underlying disease or injury that needs to be diagnosed and treated. Controlling the headache symptom will need to occur at the same time that diagnostic testing is performed to identify the underlying disease. Some of the causes of secondary headache may be potentially life threatening and deadly. Early diagnosis and treatment is essential if damage is to be limited.

The International Headache Society lists eight categories of secondary headache. A few examples in each category are noted (This is not a complete list.).

Head and neck trauma

• Injuries to the head may cause bleeding in the spaces between the meninges, the layers of tissue that surround the brain (subdural, epidural, and subarachnoid spaces) or within the brain tissue itself (intracerebral hemorrhage: intra=within + cerebral=brain, hemorrhage=bleeding).
• Edema or swelling within the brain, not associated with bleeding, may cause pain and a change in mental function.
• Concussions, where head injury occurs without bleeding. Headache is one of the hallmarks of post-concussion syndrome.
• Whiplash and neck injury also cause head pain.

Blood vessel problems in the head and neck

• Stroke or transient ischemic attack (TIA)
• Arteriovenous malformations (AVM) when they leak
• Cerebral aneurysm and subarachnoid hemorrhage. An aneurysm, or a weakened area in a blood vessel wall, can expand and leak a small amount of blood causing what is called a sentinel headache. This may be a warning sign of a future catastrophic bleed into the brain.
• Carotid artery inflammation
• Temporal arteritis (inflammation of the temporal artery)

Non-blood vessel problems of the brain

• Brain tumors, either primary, originating in the brain, or metastatic from a cancer that began in another organ
• Seizures
• Idiopathic intracranial hypertension, historically called pseudotumor cerebri, where pressure within the spinal canal increases. The cause is unknown and while it can occur in all ages, it often affects young, obese females. Idiopathic intracranial hypertension can cause significant headache and if left untreated may, on occasion, lead to blindness.

Medications and drugs (including withdrawal from those drugs)

Oral contraceptives, medications used to treat erectile dysfunction, blood pressure or other cardiac medications can all lead to or cause headaches. Medication overuse headache, occurring when pain medications are taken too frequently, can be caused by acetaminophen (Tylenol and others), aspirin, ibuprofen (Advil and others), OTC analgesics with caffeine (Excedrin and others), as well as narcotic analgesics and other prescription pain medications.

Infection

• Meningitis
• Encephalitis
• HIV/AIDS
• Systemic infections (for example, pneumonia or influenza)

Changes in the body's environment

• High blood pressure (hypertension)
• Dehydration
• Hypothyroidism
• Kidney dialysis

Problems with the eyes, ears, nose throat, teeth, sinuses, and neck

• Sinus infection
• Dental pain
• Glaucoma
• Iritis

If there is time, the diagnosis of secondary headache begins with a complete patient history followed by a physical examination and laboratory and radiology tests as appropriate.

However, some patients present in crisis with a decreased level of consciousness or unstable vital signs due to the underlying cause of the headache. In these situations, the health care professional may decide to treat a specific cause without waiting for tests to confirm the diagnosis.

For example, a patient with headache, fever, stiff neck, and confusion may have meningitis. Since meningitis can be rapidly fatal, antibiotic therapy may be started before blood tests and a lumbar puncture are performed to confirm the diagnosis. It may be that another diagnosis ultimately is found, for example, a brain tumor or subarachnoid hemorrhage, but the benefit of early antibiotics outweighs the risk of not giving them promptly.

The patient history and physical examination provide the initial direction for determining the cause of secondary headaches. Therefore, it is extremely important that patients with a new, severe headache seek medical care and give their health care professional an opportunity to assess their condition. Tests that may be useful in making the diagnosis of the underlying disease causing the headaches will depend upon the doctor's evaluation and what specific disease, illness, or injury is being considered as the cause of the headaches (the differential diagnosis). Common tests that are considered include the following:

• blood tests;
• computerized tomography (CT scan) of the neck;
• magnetic resonance imaging (MRI) scans of the head; and
• lumbar puncture (spinal tap).

Specific tests will depend upon what potential issues the health care professional and patient want to address.

Blood tests

Blood tests provide helpful information in association with the history and physical examination in pursuing a diagnosis. For example, an infection or inflammation in the body may cause a rise in the white blood cell count, the erythrocyte sedimentation rate (ESR), or C-reactive protein (CRP). These two tests are very nonspecific; that is, they may be abnormal with any infection or inflammation, and abnormalities do not point to a specific diagnosis of the cause of the infection or inflammation. The ESR is often used to make the tentative diagnosis of temporal arteritis, a condition that affects an older patient, usually over the age of 65, who presents with a sharp, stabbing temporal headache, due to inflammation of the arteries on one side of the head.

Blood tests may be used to assess electrolyte imbalance, and a variety of other potential problems involving organs like the liver, kidney, and thyroid.

Toxicology tests may be helpful if the patient is suspected of abusing alcohol, or prescription or other drugs of abuse.

Computerized tomography of the head

Computerized tomography (CT scan) is able to detect bleeding, swelling, and some tumors within the skull and brain. It also can show evidence of a previous stroke. With intravenous contrast injection (angiogram), it may also be used to look at the arteries of the brain for aneurysms.

Magnetic resonance imaging (MRI) of the head

MRI is able to show the anatomy of the brain and the layers that cover the brain and the spinal cord (meninges). It is more precise than computerized tomography. This type of scan is not available at all hospitals. Moreover, it takes much longer to perform, requires the patient to cooperate by holding still, and requires that the patients have no metal in their body (for example, a heart pacemaker or metal foreign objects in the eye).

Lumbar puncture

Cerebrospinal fluid, the fluid that surrounds the brain and spinal cord, can be obtained with a needle that is inserted into the spine in the lower back. Examination of the fluid looks for infection (such as meningitis due to bacteria, virus, fungus, or tuberculosis) or blood from hemorrhage. In almost all cases, computerized tomography is done prior to lumbar puncture to make certain there is no bleeding, swelling, or tumor within the brain. Pressure within the space can be measured when the lumbar puncture needle is inserted. Elevated pressures may make the diagnosis of idiopathic intracranial hypertension (previously known as pseudotumor cerebri) in combination with the appropriate history and physical examination.

Seek medical care if the headache is:

• The "worst headache of your life." This is the wording often used in textbooks as a cue for medical practitioners to consider the diagnosis of a subarachnoid hemorrhage due to a ruptured cerebral aneurysm. The amount of pain will often be taken in context with the appearance of the patient and other associated signs and symptoms. Too often, patients are prompted to use this expression by a health care professional and do not routinely volunteer the phrase.
• Different than your usual headaches
• Starts suddenly or is aggravated by exertion, coughing, bending over, or sexual activity
• Associated with persistent nausea and vomiting
• Associated with fever or stiff neck. A stiff neck may be due to meningitis or blood from a ruptured aneurysm. However, most patients who complain of a stiff neck have muscle spasm and inflammation as the cause.
• Associated with seizures
• Associated with recent head trauma or a fall
• Associated with changes in vision, speech, or behavior
• Associated with weakness or change in sensation on one side of the body that may be a sign of stroke
• Not responding to treatment or is getting worse
• Requires more than the recommended dose of over-the-counter medications for pain
• Disabling and interfering with work and quality of life

It is important to consider that an unusual headache may need to be evaluated by a health care professional, but in most instances, primary tension headaches may be initially treated at home.

• First steps include maximizing rest and staying well hydrated.
• Recognizing and minimizing stressful situations may be of help, if that is one of the contributing causes of the headache.
• If there has been a cold or runny nose recently, humidifying air may be helpful in allowing sinuses to drain.
• Rubbing or massaging the temples or the muscles at the back of the neck may be soothing, as might warm compresses.
• Over-the-counter pain medication may be helpful, in moderation.

Those with migraine headaches often have a treatment plan that will allow treatment at home. Prescription medications are available to abort or stop the headache. Other medications are available to treat the nausea and vomiting. Most patients with migraine headaches get much relief after resting in a dark room and falling asleep.

Patients who have secondary headaches will often need to seek medical care.