Headaches are common, varying in intensity, location, and frequency. While often benign, some may signal an underlying health condition. Diagnostic tests investigate the cause, rule out serious issues, and identify headache types for effective treatment. Understanding this process provides clarity for individuals with persistent or unusual symptoms.
Initial Medical Assessment
A healthcare provider typically begins with a thorough medical history when a patient presents with headaches. This gathers details about the headache’s onset, frequency, duration, severity, location, and any triggers or alleviating factors. Associated symptoms like nausea, vomiting, light/sound sensitivity, or visual disturbances are also discussed. This comprehensive history helps differentiate headache types and guides further diagnostic steps.
Following the history, a physical and neurological examination assesses brain, nerve, and spinal cord function. This evaluates mental status, cranial nerve function, muscle strength, coordination, and reflexes. The provider may also check vision, scalp tenderness, and signs of increased intracranial pressure. These assessments help determine if neurological deficits suggest a serious underlying cause for the headaches.
Blood tests may be ordered to check for infection, inflammation, or other systemic issues contributing to headaches. A complete blood count (CBC) can indicate infection, while ESR or CRP tests assess inflammation, particularly in individuals over 50 with new-onset headaches to rule out temporal arteritis. Blood tests can also reveal nutritional deficiencies or hormonal imbalances. These initial assessments often lead to a diagnosis for common headache types like tension or migraine headaches.
Advanced diagnostic tests, such as imaging, are considered when initial assessments raise concerns about a secondary cause. This includes sudden, severe headaches, new onset in older individuals, or headaches with neurological deficits, altered mental status, or fever. These “red flag” symptoms prompt deeper investigation to rule out conditions requiring immediate medical attention.
Advanced Diagnostic Tests
When initial assessments suggest further investigation, advanced diagnostic tests provide detailed insights into the brain and surrounding structures. These tests help identify or rule out conditions not determinable by physical examination alone.
A Computed Tomography (CT) scan uses X-rays to generate cross-sectional images of the head and brain. It is useful for detecting acute issues causing headaches, such as bleeding from a ruptured aneurysm, stroke, or large tumors. CT scans can also reveal fluid buildup (hydrocephalus) or sinus blockages. CT is often preferred in emergencies due to its speed and ability to quickly identify life-threatening conditions.
Magnetic Resonance Imaging (MRI) uses strong magnetic fields and radio waves to create more detailed brain images than CT scans. MRI is effective for identifying subtle tumors, structural abnormalities, inflammation, or neurological conditions like multiple sclerosis not visible on CT. It provides superior soft tissue contrast for comprehensive evaluation of brain structures and blood vessels. While offering greater detail, MRI takes longer than CT and may be unsuitable for patients with certain metallic implants.
A Lumbar Puncture, or spinal tap, collects a small sample of cerebrospinal fluid (CSF) from the lower back for analysis. This procedure helps diagnose infections like meningitis or encephalitis, inflammatory conditions of the nervous system, or certain autoimmune disorders causing headaches. It can also detect bleeding around the brain (subarachnoid hemorrhage) or cancers affecting the brain and spinal cord by analyzing the fluid’s composition and pressure. A lumbar puncture is typically performed after imaging tests to ensure safety and prevent complications.
An Electroencephalogram (EEG) measures the brain’s electrical activity via electrodes on the scalp. While not routine for primary headache diagnosis, it may be used if seizure activity is suspected. It helps differentiate headaches from conditions like epilepsy, especially with altered mental status or unusual neurological signs, by recording brain wave patterns that reveal abnormal electrical discharges.