Headache Causes, Symptoms, Diagnosis, Treatment, Prevention

What Is a Headache?

A headache is diffuse pain in the head not confined to the area of distribution of any nerve. By headache, we usually mean pain anywhere between the back of the head and front (like tension headache), or pain in one half of the head (like migraine or cluster headache). Head pain confined to particular parts of the head usually has more specific names, like earache, toothache, sinus headache, TMJ pain.

Headache Types and Causes

1. PRIMARY Headaches

Primary headaches, not caused by another medical condition (but triggered by certain stimuli), include:

  • Tension headache. Symptoms: pressure-like, both-sided headache, lasting from 30 minutes to 7 days, triggered by eye strain, bad posture, stress or weather conditions. Pain resolves completely between headache episodes.
  • Migraine (with or without aura). Symptoms: pulsating, one- or both-sided headache, lasting from 4 to 72 hours, aggravated by physical activity, between migraine attacks pain resolves completely; sensitivity to light, nausea. Migraine triggers: psychological factors, foods, menstruation, environmental factors.
  • Cluster headache. Symptoms: intense, one-sided pain, lasting from 15 minutes to 3 hours, forcing you to move around, appearing one or more times a day, several days or months in a row, and then resolve completely for various periods of time
  • Other types of primary headache

2. SECONDARY Headaches

Secondary headache results from another medical condition or other obvious cause.

Causes of a SUDDEN (ACUTE) HEADACHE, lasting from hours to weeks:

  • Hair accessories, hats, helmets
  • Dehydration
  • Food related causes (check migraine headache triggers)
  • Sinusitis
  • Medications and other substances or their withdrawal: nitroglycerin, drug allergies, estrogen, illegal drugs (cocaine, marijuana), smoking, alcohol (hungover), caffeine, nitric compounds (glue), carbon monoxide
  • Constant coughing
  • Premenstrual syndrome (PMS)
  • Heat stroke, burns
  • Infections: influenza, pneumonia, childhood infections, tonsillitis (strep throat), sepsis (blood poisoning)
  • Concussion, whiplash and other head and neck injuries
  • Disorders of the neck, skull, eye, ear, nose, paranasal sinuses, mouth, throat, temporomandibular (TMJ) joint (head pain)
  • Procedures: lumbar punction, dialysis, angiography
  • Disorders within the head (intracranial disorders): meningitis, brain abscess, stroke, transient ischemic attack (TIA), seizures, ruptured brain artery aneurysm
  • Hypoxia (lack of oxygen in the body): severe pneumonia, mountain sickness (high altitude), poisoning with carbon monoxyde (CO) or cyanide
  • Poisons and toxins, like clupeotoxin  in contaminated fish
  • Motion sickness, diving (barotrauma)
  • Eclampsia – a headache with seizures during or after delivery
  • Psychiatric disorders
  • …and other causes

Causes of a RECURRENT or PERSISTENT (CHRONIC) HEADACHE, lasting months to years:

  • Constipation
  • Disorders in the neck, skull, eye, ear, nose, paranasal sinuses, mouth, throat, temporomandibular (TMJ) joint
  • Anemia, venous thrombosis, hypoglicemia, vitamin deficiencies
  • Alcoholism, smoking, illegal drugs
  • Food related causes, like celiac disease, malnutrition
  • Medications, like ergotamine or opiate (codeine) overuse, nitroglycerin, birth control pills
  • Chronic infections: HIV/AIDS
  • Temporal arteritis, disorders of carotid artery (carotidynia or lower half headache), vertebral or basilar artery
  • Kidney or liver failure
  • Cancer, leukemia
  • Hypothyroidism
  • Adrenal disorders: Conn’s syndrome, Cushing’s syndrome
  • T4 syndrome – an injury of the 4th spinal vertebra, resulting in back and head pain and abnormal sensations and pain in one or both arms
  • Disorders within the head: brain tumor or cyst (toxoplasma, echinococcus), neurosarcoidosis
  • Fatigue, fibromyalgia
  • High blood pressure
  • Chronic poisoning (lead)
  • Developmental disorders of the brain or spinal cord: hydrocephalus, Chiari malformation, syringomyelia
  • Psychiatric disorders
  • …and other causes

3. CRANIAL NEURALGIA (nerve pain):

Cranial neuralgia is pain arising from certain nerves:

  • Trigeminal neuralgia – intense, electro-shock-like, one-sided facial pain
  • Glossopharyngeal neuralgia – shooting throat pain triggered by swallowing or coughing
  • Occipital neuralgia – continuous and, occasionally, shooting one-sided pain on the back of the head, caused by disorders in the neck
  • Burning mouth syndrome

Headache Symptoms

The cause of a headache can be suspected from its characteristics and accompanied symptoms:

  • Both-sided diffuse headache can be tension headache, systemic disease, a disorder within the head
  • One-sided headache can be migraine, cluster headache, neuralgia, glaucoma, mumps, TMJ disorder or other localized disorder in the head, face or neck
  • Aura (for example, flashing lights within an hour before a headache onset): migraine, seizures
  • Sharp, shooting head pain: trigeminal neuralgia, disorder of temporomandibular (TMJ) joint, multiple sclerosis
  • Sudden severe headache: cluster headache, intracranial bleeding, high blood pressure (pheochromocytoma)
  • Pulsating or throbbing headache: migraine, temporal arteritis, iron deficiency anemia, adverse reaction to monosodium glutamate (MSG), or nitroglycerin
  • Morning headache: sleep apnea, restless sleep, forced sleeping position, basilar migraine, spinal disorders
  • Headache with neck pain or stiffness: torticollis, spinal disorders, meningitis, encephalitis
  • Headache with pain, tingling, numbness or weakness in the arm(s) speak for a disorder in the cervical spine or stroke
  • Headache with unequal size of pupils, or numbness, tingling, weakness, paralysis on one side of the head or the body speak for intracranial disorder, like brain tumor or stroke
  • Facial pain can be from sinusitis, trigeminal neuralgia, multiple sclerosis or localized facial disorders

Headache Diagnosis: Tests and Investigations

See a doctor as soon as possible, if:

  • You have a sudden severe (or even mild or temporary) headache, since it can originate from a serious disorder in your head
  • Your headache is different or worse than usual
  • Your headache is accompanied by abnormal sensations, muscle weakness, stiff neck
  • Your headache has appeared after an injury, taking medications or drugs

In above cases, go to Emergency Room (ER) directly. Do not drive with a headache! Ask someone to drive you or call an ambulance (911 in US).

The doctor will likely ask you:

  • Where do you feel a headache, how does it feel, when and how fast did it appear and how long does it last? Is it worse at any part of the day?
  • Any nausea, fever, abnormal sensations, muscle weakness, neck stiffness?
  • What could be the cause: medications, smoking, alcohol, coffee, illegal drugs, poisoning, chronic disease, surgery? What is your diet?
  • Have you taken a painkiller and have it helped?
  • Chronic headaches in your family?

Physical examination

After examination, including neurological examination and checking your body temperature and blood pressure, your doctor might give you a diagnosis, like a migraine or medications side effect, without any test.

You can expect further investigations, if you have (4):

  • New, rapid onset, different or worse headache than usual
  • Neurological symptoms, like vision disturbance or limb weakness
  • Headache aggravated by posture, exertion, coughing
  • Neck stiffness, fever or weight loss
  • AIDS, cancer or coagulation disorder (venous thrombosis)


  • Skull X-ray can be done after a head injury, when a skull fracture on the top of the head is suspected, since CT or MRI can not show it reliably(5). Skull X-ray can also reveal foreign metallic objects in the head and metastases in the skull.
  • Sinus X-ray can be done to check for sinusitis.X-ray of the mastoid can be done in suspected mastoiditis.
  • X-ray of the cervical spine can be done, when spinal arthritis is suspected.
  • Chest X-ray, when pneumonia or lung cancer is suspected. Most brain tumors originate from lung cancer.

X-ray cannot reliably show most other headache related disorders, so usually a CT or MRI are necessary for diagnosis.

CT of the head:

  • To check for skull fracture after a head injury
  • To check forbleeding in the head after a head injury or in suspected ruptured aneurysm (sudden, thunderclap headache) or stroke (abnormal sensations, limb weakness)
  • To check for brain tumor or other abnormal mass, like a cyst or abscess (pus collection)
  • Before a lumbar puncture in suspected meningitis or encephalitis (if a brain mass is found, lumbar puncture should not be done) (6)

CT may not reliably reveal:

  • Fractures on the top of the skull (X-ray can be done, instead)
  • Brain tumors or other abnormal masses on the back of the brain
  • Disorders of small vessels or venous sinuses, disorders of hypophysis
  • Meningitis

A CT angiography (CTA), a CT with a contrast injected into the (arm) vein can show arterial disorders,like a brain aneurysm, arterial dissection, arteriovenous malformation (AVM) (7), cyts (toxoplasma).

A magnetic resonance imaging (MRI) can reveal:

  • Most brain tumors, cysts, abscesses
  • Large and medium sized brain vessel disorders
  • Encephalitis
  • Multiple sclerosis

MRI may not reliably show:

  • Bleeding in the head in the first 12 hours
  • Skull fractures
  • Small vessel disorders
  • Meningitis

A magnetic resonance angiography (MRA) can usually cleraly reveal arterial disorders,like a brain artery aneurysm, dissection, stenosis or arteriovenous malformation (AVM) (8).

A magnetic resonance venography (MRV) can reveal disorders of venous sinuses, like thrombosis (8).

Brain Angiography

A brain angiography, an X-ray investigation with a contrast substance injected into a carotid artery (via catheter inserted through the artery in the groin), is sometimes necessary before surgery.

Spinal tap (lumbar puncture) to check for (9):

  • Infectious meningitis or encephalitis
  • Neuroborreliosis (Lyme disease)
  • Neurosyphilis
  • Carcinomatous meningitis
  • Bleeding under meninges (subarachnoidal bleeding) if you have had a thunderclap headache, but CT was negative

Blood Tests

  • Antibodies or blood culture in suspected infection, like influenza or meningitis, Epstein-Barr virus (EBV) (10), Lyme disease
  • Blood sugar in suspected hypoglycemia
  • Blood cells, minerals, iron, vitamin B12, liver enzymes, bilirubin, urea to rule out anemia, dehydration, liver or kidney disease, leukemia
  • Hormone levels:thyroid hormones, estrogen, prolactin, adrenaline (epinephrine)
  • Sedimentation rate (ESR) and CRP to check for temporal arteritis
  • Carboxyhemoglobin level in suspected carbon monoxide (CO) poisoning
  • Arterial blood gases (oxygen, carbon dioxide) in suspected hypoxia

Urine Tests

  • Proteins, minerals to check for kidney disorders
  • Glucose to check for diabetes
  • Certain hormones
  • Certain substances to check for painkillers or illegal drugs abuse

Other Tests and Investigations in Headache

  • X-ray of the teeth in suspected teeth disease
  • Ear examination to check for infection of the middle ear
  • Throat inspection, laringoscopy
  • Eye tests in suspected refractive error or glaucoma
  • Doppler ultrasound in suspected carotid artery dissection
  • Biopsy of the temporal artery in suspected giant cell arteritis
  • Electroencephalogram (EEG) in suspected encephalitis
  • Antibodies to Treponema pallidum to rule out neurosyphilis

Second Opinion

The cause of a headache may be sometimes hard to find. Before asking for a second opinion, think if you have removed all possible causes or triggers of your headache.

Headache Treatment

Treatment of headache depends on its type and severity, and may include:

  1. General measures
  2. Non-prescription medications
  3. Prescription medications
  4. Treatment of the cause


Bed rest in a quiet, dark room may help in migraine, headache due to infectious diseases, preeclampsia, or lumbar puncture, but might not be helpful in tension or cluster headache, stroke or chronic headache.

Fluid intake (water, unsweetened herbal tea, or sport drinks containing sodium) is recommended in tension type headache, migraine, constipation, diarrhea, dehydration, hangover, hypoglycemia and infectious diseases, to maintain good hydration. Sport drinks should be avoided when increased pressure within the head is suspected (in head injury, brain tumor, aneurysm, stroke, meningitis) and if your doctor has instructed you to limit fluid and salt intake. Alcohol and caffeinated drinks should be avoided in any type of headache. Small amount of caffeine may help in mild migraine, though, but long term ‘treatment’ with coffee may aggravate migraine.

A warm compress placed on the forehead for three minutes and then a cold compress for 30 seconds (repeating this three times, several times a day) may help in sinus headache.

A cold compress or ice pack on the neck may help in tension-type headache or migraine.

Massage of the temples or other parts of the head and neck can help in migraine or tension headache.

A soft cervical collar can be used at night in spinal arthritis and in whiplash.


OTC painkillers may help in mild headache.

ACETAMINOPHEN or PARACETAMOL (Tylenol) may help in  tension headache. Precautions: Do not take acetaminophen in hangover, chronic liver disease or if you consume large amounts of alcohol, and never take it in large amounts, since it can cause severe liver damage.

ANTIHISTAMINES,like diphenhydramine (Benadryl), when taken with painkillers, can help in night headaches.

EXCEDRIN MIGRAINE (acetaminophen + aspirin + caffeine) can help in migraine or cluster headache. Precautions: Excedrin should not be taken in active peptic ulcer. It may also trigger migraine.

NSAIDs (Non-Steroidal Antiinflamatory Drugs) can help in tension headache:

  • ASPIRIN (Alka-Seltzer effervescent tablets). Precautions: Aspirin should not be taken by children under 16 years of age (it can cause a life threatening Reye’s syndrome – liver failure), in obvious or suspected bleeding, after surgery, or in combination with anticoagulants.
  • IBUPROFEN (Advil, Motrin) or NAPROXEN SODIUM (Aleve).
    • Precautions: NSAIDs should not be used in peptic ulcer or GERD.


Prescription medications are intended for moderate or severe headache.

ANTIBIOTICS may be needed in bacterial infections, like bacterial sinusitis or meningitis.

ANTIEMETICS, like metochlopramide (Reglan) and prochlorperazine (Compazine) can prevent nausea and vomiting, common in migraine and during treatment with opiates.

ANTIHISTAMINES, like promethazine (Phenergan) and hydroxyzine (Vistaril) in combination with painkillers can help in night headaches.

CALCIUM CHANNEL BLOCKERS, like verapamil (Isoptin) and diltiazem (Dilacor), can help in cluster headache.

CHLORPROMAZINE intravenous injection(Thorazine) can be effective in severe acute headache. Precautions: Chlorpromazine can cause drowsiness or drop of blood pressure.

ERGOTS narrow the arteries in the head (and other parts of the body, especially in the heart).

  • Dyhidroergotamine mesylate (DHE 45, Migranal) as intravenous injection or nasal spray may be used in severe migraine, cluster headache and chronic daily headache.
  • Ergotamine (Ergostat, sublingual), and ergot with caffeine (Cafergot) may help in migraine.
    • Precautions: DHE should not be used together (within 24 hours) with other ergot medications or triptan, in  pregnancy, coronary heart disease, arterial disorders, uncontrolled hypertension, basilar migraine.

LIDOCAINE (local anesthetic, as nasal drops or spray) may help in cluster headache or trigeminal neuralgia.

MAGNESIUM SULFATE intravenous injection can help in acute migraine.

MIDRIN (in capsules) is a combination of acetaminophen (a pain killer), dicloralphenazone (a sedative), and isomethepten mucate (a blood vessel constrictor). It can help in tension headache and migraine. Precautions: should not be taken in ischemic heart disease, high blood pressure, glaucoma or kidney disease.

NSAIDs (Non-Steroidal Antiinflammatory Drugs), like ketoprofen (Orudis) or naproxen (Naprosyn) can help in mild to moderate tension headache or migraine.

OPIATES, like morphine, may be used in severe headache, when other medications have failed. Long acting (extended-release) morphine sulfate (Kadian) can be used in chronic daily headache. Precautions: Overuse of opiates may cause medication overuse headache (MOH). Opiates regularly cause nausea, constipation, drowsiness and may be addictive. Opiates should not be used in suspected increased intracranial pressure (head injury, stroke, meningitis, brain mass).

OXYGEN (100%) INHALATION applied through an oxygen facial mask (pocket oxygen canisters exist), may abort cluster headache within 15 minutes.

TRIPTANS  stimulate 5-hydroxytriptamine (5-HT or serotonin) receptors in the blood vessels in the head thus causing their narrowing. They can help in tension headache, migraine or cluster headache. They are available as tablets, nasal sprays and intravenous injections and should be taken early after headache begins to have maximal effect. Sumatriptan (Imitrex) intravenous injection can relieve migraine in 5-10 minutes. Precautions: Triptans should not be used on the same day as ergots. They should be not used by individuals who have coronary artery disease or have had stroke.


Treatment of eventual underlying disorders (see causes of headache above) can relieve headache.

Headache Prevention


  • Drinking enough water (dehydration may cause headache), having regular meals and sleeping pattern
  • Regular physical exercise on the fresh air, but avoiding excessive physical strain
  • Making breaks in prolonged eye strain (computer work, study)
  • Avoiding migraine triggers, like certain foods and stress
  • Biofeedback is a learning method to control body functions, like muscular tension, using your mind and instruments that measure achieved effect. This technique may help in chronic migraine and tension headache.
  • Avoiding excessive use of painkillers to prevent medication overuse headache (rebound headache)


  • Beta blockers, like propranolol (Inderal)
  • Butterbur root extract and feverfew herbal supplement
  • Methysergide (Sansert)
  • Pizotifen (Sandogran)
  • Riboflavin (vitamin B2)
  • Steroids, like dexamethasone (intravenous injection) may prevent migraine or cluster headache attacks.

The following methods have not provided reliable headache relief during clinical trials:

  • Acupuncture
  • Botulinum toxin A
  • Neck manipulation – can be dangerous, especially if not done properly; stroke or even death were reported
  • Transcutaneous Electrical Nerve Stimulation (TENS)

Related Articles:


  1. Headache definition  (aafp.org)
  2. Headache causes  (mayoclinic.org)
  3. Medications that can cause headache  (webmd.com)
  4. Investigations in skull fracture  (emedicine.medscape.com)
  5. CT before lumbar puncture in suspected meningitis  (emedicine.medscape.com)
  6. CTA and MRA to check for brain aneurysm  (emedicine.medscape.com)
  7. MRA and MRV of the head  (aetna.com)
  8. Indications for lumbar puncture in a headache  (emedicine.medscape.com)
  9. EBV and new daily persisting headache (NDPH)  (journalarchive.jst.go.jp)
About Jan Modric (209 Articles)
Health writer

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