Headaches
Why do headaches occur? Everything you need to know about headaches: causes, symptoms, and treatment.
Symptoms and Causes
A headache refers to pain and discomfort localized in any part of the head. It is one of the most common nervous system disorders and a frequent reason for medical consultation in pediatric patients.
Headaches are classified based on their duration as:
- Episodic or acute headaches: Occur less than 15 days per month.
- Chronic headaches: Occur more than 15 days per month.
Based on their origin, there are two main types of headaches:
- Primary Headaches: These headaches originate within the nervous system itself.
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- Migraine: Very intense, unilateral, and throbbing attacks of pain. Worsens with movement and improves with rest.
- Tension headache: A pressing pain that affects the entire perimeter of the skull, predominantly in the forehead and neck. It is mild to moderate in intensity and can last several days. It is the most common type.
- Trigeminal-autonomic headaches: Unilateral, very intense pain located in the area innervated by the trigeminal nerve. These headaches are short in duration and occur several times a day.
- Cluster headache: Severe, unilateral pain, typically around the eye, lasting less than three hours and occurring multiple times a day over several months each year.
- Paroxysmal hemicrania: Very intense, unilateral headaches, usually behind the eye. They last less than 30 minutes but occur multiple times per day.
- Short-lasting unilateral neuralgiform headache attacks (SUNCT/SUNA): Intense unilateral pain lasting a few minutes. Can occur between 3 and 200 times per day. Very rare.
- Cough headache: Triggered by coughing or increased intracranial pressure due to sneezing, straining, or lifting weights. Lasts less than 30 minutes.
- Exercise-induced headache: Throbbing pain lasting between five minutes and 48 hours.
- Coital or sex-related headache: Bilateral headache that peaks during orgasm and can last from minutes to hours.
- Cold-stimulus headache: Triggered by exposure to something very cold. It is a stabbing, unilateral pain of short duration.
- Hypnic headache: Occurs only during sleep, waking the patient up. Persistent and can last up to two hours.
- Trigeminal neuralgia: Sharp, stabbing, or electric-like pain attacks on one side of the face. Sudden onset and termination, lasting only a few seconds.
- Secondary Headaches: These are symptoms of an underlying condition.
Symptoms
The main symptom of a headache is head pain, which varies in nature depending on its classification. Additionally, some headache types may present with other manifestations:
- Migraine Symptoms:
- Nausea and vomiting
- Sensitivity to light and noise
- Prodrome: Warning signs appearing one or two days before the attack
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- Constipation
- Increased urination frequency
- Neck stiffness
- Mood changes
- Fluid retention
- Food cravings
- Frequent yawning
- Aura: Neurological symptoms preceding the pain:
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- Flashes, blind spots, distortions, or blurred vision
- Tingling that starts in the fingers and spreads to the face
- Language disturbances or weakness on one side of the body
- Postdrome: Fatigue, confusion, and irritability after the attack. Occasionally, euphoria.
- In children, migraines typically occur without aura, are often bilateral (frontal-parietal), and shorter in duration. They may be accompanied by dizziness, blurred vision, pallor, sweating, or flushing.
- Trigeminal-autonomic Headache Symptoms:
- Red eye
- Tearing
- Nasal congestion or blockage
- Rhinorrhea (nasal discharge)
- Facial sweating
- Secondary Headache Symptoms: Depending on the underlying condition, headache may be associated with:
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- Dizziness
- Fatigue
- Difficulty concentrating or memory problems
- Fever
- Severe vomiting
- Worsening in a horizontal position
- Manifestation upon standing
- Tinnitus (ringing in the ears)
Causes
Headaches result from the activation of peripheral extracranial nociceptors. These nociceptors are free nerve endings that respond to tissue damage.
The exact mechanisms underlying primary headaches remain unknown. Migraines are believed to have a genetic component and arise from the activation of sensory nerves that release peptides or serotonin, leading to vasodilation and inflammation in the arteries, meninges, and dura mater. The aura phase is thought to be caused by increased neuronal activity in the cerebral cortex, known as cortical spreading depression. Tension headaches are linked to the activation of peripheral nerves in the head and neck muscles, while cluster headaches involve an overactivation of the trigeminal nerve and hypothalamus of unknown origin.
Despite their uncertain causes, primary headaches have common triggers:
- Muscle tension
- Stress, especially in tension headaches, cluster headaches, and migraines
- Alcohol, especially red wine (due to tannins)
- Dehydration or fasting
- Strong odors
- Bright lights
- Weather changes, especially barometric pressure shifts
- Hormonal changes (menstruation, ovulation, oral contraceptive use)
- Certain foods (chocolate, banana, nuts, citrus, sausages, aged cheese, caffeine, monosodium glutamate, spicy foods)
- Sleep disturbances
- Certain medications (vasodilators, nitrates)
- Everyday stimuli like chewing, talking, or brushing teeth (in trigeminal neuralgia)
Secondary headaches often result from meningeal or vascular irritation due to external factors:
- Head or neck trauma
- Vascular disorders (ischemic stroke, brain hemorrhage, aneurysm rupture, arteriovenous malformation, thrombosis)
- Intracranial pressure abnormalities
- Tumors
- Substance use or withdrawal
- Infections (sinusitis, meningitis, encephalitis, brain abscess)
- Metabolic disorders (hypothyroidism, hypertension, hypoxia, dialysis)
- Structural abnormalities (ear infections, glaucoma)
Risk factors
Factors that increase the risk of developing headaches include the following:
- Family history.
- Age: more common during adolescence and the second decade of life.
- Sex: headaches are more frequent in women. In childhood, they are more common in males.
- Obesity.
- Anxiety or depressive disorders.
- Sleep disturbances.
- Medication overuse (analgesics).
- Pregnancy, menstruation, or menopause.
- Use of hormonal contraceptives or hormone replacement therapy.
Complications
Severe primary headaches, such as migraines or cluster headaches, can be disabling and may significantly interfere with a person’s daily life. In addition, migraine with aura may lead to cerebral infarction (stroke). Secondary headaches, in turn, may be a symptom of a very serious or even life-threatening condition, such as meningitis.
Warning signs indicative of a headache due to a serious underlying cause include:
- Very intense, explosive-onset pain.
- Progressive worsening of pain over several days or weeks.
- Headache accompanied by altered level of consciousness, neck stiffness, seizures, or other abnormal neurological signs.
Prevention
Certain measures can be taken to help prevent the occurrence of primary headaches:
- Establishing regular sleep schedules.
- Maintaining adequate nutrition and hydration.
- Relaxation techniques to control stress.
- Avoiding common triggers.
- Regular physical exercise.
- Reducing or avoiding alcohol and tobacco consumption.
Which Doctor Treats Headaches?
Headaches are diagnosed and treated by Neurology and Pediatric neurology specialists.
Diagnosis
The diagnosis of headache is based on the following examinations:
- Clinical history: essential for classifying the type of headache. It is necessary to define all characteristics of headache episodes, such as exact pain location, type of pain, duration and frequency of episodes, time course, presence of associated symptoms, prodromal symptoms or auras, and usual triggering or aggravating factors.
- Physical and neurological examination: blood pressure and heart rate are measured, as well as coordination, vision, motor strength, and sensory function. In addition, fundoscopic examination, paranasal sinuses, and the neck are assessed to rule out secondary causes of headache.
If an underlying disorder causing the headaches is suspected, additional tests may be performed:
- Complete blood count (CBC): elevation of C-reactive protein or erythrocyte sedimentation rate is indicative of inflammatory or infectious processes.
- Skull radiography: X-ray imaging may show signs of bone lesions or sinusitis.
- Cranial computed tomography (CT) or magnetic resonance imaging (MRI): more precise and detailed brain imaging is obtained, allowing identification of signs of hemorrhage, trauma, tumors, thrombosis, vascular inflammation, aneurysms, among other possible disorders.
- Lumbar puncture: cerebrospinal fluid is obtained via needle aspiration from the spinal canal to measure pressure and assess for inflammation or infection. It is performed when meningitis, encephalitis, or increased intracranial pressure is suspected.
Treatment
In the case of secondary headaches, the underlying cause is treated. For primary headaches, several options are available:
- Lifestyle modification: in the case of migraine, adopting the preventive measures mentioned above helps reduce the frequency of episodes.
- Pharmacological treatment of acute headaches:
- Nonsteroidal anti-inflammatory drugs (NSAIDs): relieve pain in mild to moderate headaches.
- Triptans: used in migraine attacks or cluster headaches that do not respond to NSAIDs. They act on serotonin receptors, inhibiting pain transmission.
- Treatment of chronic headaches, mainly migraines and cluster headaches:
- Preventive pharmacological treatment: taken daily to reduce the frequency and intensity of episodes. The specific treatment depends on each patient’s profile. Medications may include calcium channel blockers, antiepileptics, antihypertensives, antidepressants, or monoclonal antibodies.
- Botulinum toxin injections: block peripheral sensitization of nociceptors.
- Neurostimulation: involves modulating nociceptive activity through transcutaneous electrical nerve stimulation of the supraorbital nerve or the vagus nerve. A portable self-administered device is used.
- Nerve block: a local anesthetic is injected into pericranial nerves to inhibit pain generation and conduction.
- Neuromodulation: involves the implantation of electrodes in the occipital or maxillary nerves to block the transmission of nociceptive impulses.


























































































