Headache Conditions and Diagnosis

Understanding headache disorders

Headache disorders are common, but they are not all the same. Accurate diagnosis matters because different headache conditions behave differently, respond to different treatments, and carry different risks.

This page brings together clear, evidence-based explanations of headache disorders, focusing on how they are diagnosed, how they differ, and when specific features should prompt further evaluation. Resources are written and curated by headache specialists at the Ottawa Headache Centre.

If you are new to headache care, you may wish to start with migraine. If your symptoms are unusual, positional, one-sided, or associated with neurological features, the sections below can help orient you.

Migraine

Migraine is a neurological disorder characterized by recurrent headache attacks and associated symptoms such as nausea, light sensitivity, and sound sensitivity. Some people experience migraine aura, which reflects transient changes in brain activity.

OHC resources

Migraine diagnosis and biology

Migraine aura

Chronic migraine

Vestibular migraine

Headache in pregnancy and during breastfeeding/lactation

Cluster headache and trigeminal autonomic cephalalgias (TACs)

Cluster headache and related trigeminal autonomic cephalalgias (TACs) are severe one-sided headache disorders associated with autonomic symptoms such as tearing, nasal congestion, or restlessness. These conditions are often misdiagnosed as migraine but require different management.

OHC resources

Cluster hadache

Trigeminal autonomic cephalalgias

CSF dynamic disorders - IIH and SIH

Disorders of cerebrospinal fluid (CSF) dynamics can cause headaches that are often positional (worse upright or worse lying down) and may be associated with visual changes, tinnitus, or neurological symptoms.

OHC resources

IIH (idiopathic Intracranial Hypertension)

SIH (Spontaneous Intracranial Hypotension) and CSF-Leak

Other headache disorders

These headache and facial pain disorders are commonly encountered in practice and have clear diagnostic features. They are grouped together here because they represent distinct conditions that sit outside the major migraine, cluster/TAC, and CSF disorder categories.

OHC Resources

Trigeminal neuralgia and other cranial neuralgias

Headache associated with sexual activity

Medication-overuse headache

Thunderclap headache

Trusted external resources

The following organizations provide high-quality patient education, advocacy, and guideline-based information. They are included here as trusted complements to Ottawa Headache Centre resources.

Migraine and general headache education

Migraine Canada - Canadian patient education and advocacy organization. A leader in patient resources.

Migraine Québec - French-language migraine education and advocacy.

Canadian Headache Society Guidelines and Position Statements - Canadian national authority of headache medicine, producing contemporary clinical guidelines and position statements.

European Migraine and Headache Alliance - a world-leading European patient advocacy and education.

Cluster headache

Clusterbusters - a patient advocacy and educational organization.

Migraine Canada: cluster headache - section on Migraine Canada.

Association of Migraine Disorders: cluster headache - section from the Association of Migraine Disorders.

CSF-leak and spontaneous intracranial hypotension

Spinal-CSF-Leak patient pamphlet - patient-friendly overview of CSF leaks.

Spinal CSF-Leak Canada - Canadian patient support and education.

Spinal CSF-Leak Foundation - International education and advocacy.

CSF-Leak Association - UK-based patient education organization.

Not sure where to start?

If you are looking for a more guided, patient-friendly overview, visit the Patients → Headache Disorders section, which walks through common headache conditions in a step-by-step way.

Disclaimer

This material is provided for educational purposes and does not replace independent clinical judgment or institutional protocols. Management decisions remain the responsibility of the treating clinician.