What Causes Headaches?

What Actually Causes Headache Pain?

The brain tissue itself is not pain-sensitive in the way the structures surrounding it are. Headache pain can arise from the meninges—the membranes covering the brain—blood vessels and their associated pain pathways, trigeminal nerve pathways, muscles and other tissues of the head and neck, and upper cervical nerves.

Signals from these structures travel through the nervous system and interact with pain-processing networks. Those networks influence how intense pain feels and which other symptoms accompany it. Headaches are not simply blood vessels expanding or contracting: nerve signaling, inflammatory mediators and changes in pain processing also matter.

What Are the Most Common Types of Headaches?

Primary headache disorders are conditions in their own right, rather than symptoms of another disease. Recognizing their patterns helps distinguish migraine vs tension headache and less common disorders.

Migraine

Migraine may cause throbbing or pulsating pain, nausea, light sensitivity and sound sensitivity. Pain can be one-sided or affect both sides; activity often makes it worse. Some people experience aura, such as temporary visual or sensory symptoms. Migraine involves complex neurological mechanisms, including trigeminovascular pathways and signaling by CGRP, a peptide involved in pain transmission. It is not just a severe ordinary headache.

Tension-Type Headache

This often feels like bilateral pressure or tightness—a band around the head. Muscular tenderness may accompany it, but muscle tension alone does not explain every case. Pain-processing mechanisms also contribute. Compared with migraine, typical tension-type headache is less likely to cause nausea or worsen with routine activity.

Cluster Headache

Cluster headache produces very severe, usually one-sided pain around the eye, often with tearing, nasal congestion or restlessness. Attacks occur in recurring clusters and are generally shorter than migraine attacks. Unlike many people with migraine who prefer lying still, someone having a cluster attack may pace or feel unable to remain still.

What Other Medical Conditions Can Cause Headaches?

Secondary headaches arise from another condition. Viral infections, appropriately diagnosed sinus disease, certain medication effects and caffeine withdrawal can cause headache. Frequent use of headache-relief medication can contribute to medication-overuse headache. Dehydration and sleep disturbances may trigger or worsen headaches, including an underlying primary headache disorder.

Cervicogenic headache is referred pain from a disorder affecting the neck; upper cervical and trigeminal pathways help explain why neck problems can be felt in the head. Other nerve-related pain disorders can cause brief stabbing or electric sensations. Neck pain alone, however, does not establish cervicogenic headache.

Severe blood pressure elevations can cause headache in some clinical contexts, particularly a hypertensive emergency. Ordinary mild or moderate hypertension usually does not explain recurrent headaches. A new headache should not automatically be labeled sinus pain, stress or high blood pressure without assessment.

Why Can Headaches Change During Perimenopause and Menopause?

Estrogen fluctuations can influence migraine susceptibility and pain-processing pathways. During perimenopause, unpredictable hormone changes may make attacks more frequent or less predictable. Some women improve after menopause, when ovarian hormone fluctuations settle, while others continue to have migraine.

Not every headache during menopause is hormonally caused. Sleep disruption, stress, hot flashes, medication changes and other medical conditions can all matter. Explore perimenopause and migraine, menstrual migraine and estrogen and the brain for related context. Our menopause and sleep and brain-fog guides explain overlapping symptoms without assuming one cause.

How Does a Neurologist Evaluate Headaches?

Evaluation begins with a careful history and neurological examination. A clinician asks when pain began, whether onset was sudden or gradual, how long it lasts, where it occurs and how often it returns. Visual, sensory or other neurological symptoms, changes in the pattern and all medications—including nonprescription products—are important.

A headache diary can help document timing, associated symptoms and medication use. MRI or other testing may be appropriate in selected circumstances. Routine imaging is not necessary for every person with a typical primary headache pattern and a normal neurological examination; warning signs and individual history guide that decision.

What Headache Warning Signs Require Medical Attention?

Call 911 for a sudden severe thunderclap headache, or headache with acute stroke-like symptoms such as weakness, confusion or difficulty speaking. Do not assume new neurological symptoms are familiar migraine aura.

• Headache with fever and neck stiffness requires urgent evaluation.
• A new headache during pregnancy or postpartum needs prompt medical assessment.
• New headache after age 50, especially with vision changes or jaw pain, warrants prompt evaluation.
• Progressive or substantially changing patterns, cancer or immunosuppression, or a new headache after significant head injury need assessment.

The urgency depends on symptoms and circumstances. Our new-headache guide explains why a changing pattern should not simply be attributed to menopause.

When Should You See a Doctor for Recurrent Headaches?

Frequent, disabling, persistent or changing headaches deserve evaluation. Identifying the type guides discussion of acute medications, preventive treatments, lifestyle measures and contributing conditions. No single treatment works for every headache type. Bring your symptom pattern and medication list to the visit so the plan addresses your diagnosis and individual needs.