Headache — causes, types, symptoms, diagnosis and treatment

Common causes and triggers

Headaches have many possible causes. Frequent triggers include systemic illness such as fever, prolonged visual tasks such as watching television or using computer screens and other screens for long periods, fatigue and lack of sleep, and persistent stress. They may also occur as a symptom of other neurological problems involving the nerves and brain, for example in some people with epilepsy. Other triggers include dehydration, skipped meals, alcohol, certain foods and strong odors.

Types and classification

Medicine groups headaches into broad categories. Primary headaches arise without another underlying disease and include conditions such as migraine, tension-type headache and cluster headache. Secondary headaches are symptoms of another disorder (for example infection, vascular problems or head injury). A related group includes cranial neuralgias and facial pain syndromes, where a specific nerve is the source of sharp, stabbing pain. Classification tools, such as the International Classification of Headache Disorders, list many distinct forms and help clinicians match a patient’s pattern of symptoms to likely diagnoses.

Symptoms and diagnosis

Descriptions that guide diagnosis include pain location (one-sided, both sides, around the eyes), quality (throbbing, pressing, sharp), intensity, duration and associated features such as nausea, light or sound sensitivity, visual changes or weakness. A careful history and physical examination are usually sufficient. When alarm signs are present — sudden severe onset, fever with neck stiffness, confusion, new focal neurological deficits, symptoms after head trauma or progressive worsening — imaging or further tests may be needed. Identifying triggers and patterns is key to managing recurrent headaches.

Treatment and prevention

Treatment depends on the type and severity. Many everyday headaches respond to simple measures: rest, hydration, sleep, cold or warm compresses and short-term use of over-the-counter analgesics such as aspirin or acetaminophen and nonsteroidal anti-inflammatory drugs. Migraines may require specific prescription drugs (triptans, antiemetics, or preventive medications), while cluster headaches and neuralgias often need targeted treatments. Non-drug approaches — sleep regularity, stress management, biofeedback, physical therapy and avoiding identified triggers — are important. Caution is needed to avoid medication-overuse headache, which can result from frequent use of acute pain medications.

When to seek urgent care and notable facts

Seek immediate medical attention for thunderclap headaches (very sudden and severe), headaches accompanied by fever and neck stiffness, changes in consciousness, new neurological symptoms such as weakness or slurred speech, or after significant head injury. Headache disorders, particularly migraine, are a major cause of reduced quality of life and work limitation worldwide; recognizing specific patterns improves treatment outcomes. For more information or resources on common triggers and headache types, consult trusted clinical guides and educational materials from health organizations or specialists in headache medicine (fever resource, general guidance on watching television and visual strain, computer screens ergonomics, screens, stress management stress, neurological context neurological, anatomy of nerves and the brain, conditions like epilepsy, primary headache types such as migraine, tension-type headache and cluster headache, and medication topics including analgesics and aspirin).