Headache
What a Normal Scan Can (and Cannot) Tell You
General information from an emergency physician. It adds to your discharge papers and does not replace them or your own doctor. What this site is and isn’t
Key Takeaways:
- Most emergency-department headaches are not caused by brain damage.
- Headaches commonly return within 48 hours after emergency treatment.
- A sudden, worsening, or neurologically different headache needs immediate reassessment.
About Your Diagnosis & ED Workup
About six in ten ER headaches are migraine, tension, or another primary headache. These can be severe without brain damage.
A head CT looks for bleeding, large growths, and swelling that pushes on the brain.
A normal CT does not find every dangerous cause. Some blood clots, torn neck arteries, infections, and swollen blood vessels need other tests.
CT finds bleeding around the brain best in the first six hours. It finds less after that time.
First Steps & Evidence-Based Home Care
Use only the headache medicine in your discharge plan. Frequent use is linked with frequent headaches. Experts debate which one starts the cycle.
A practical limit is about two treatment days per week on average.
Opioids and butalbital mixtures are not advised for migraine. They can worsen medicine-overuse headaches.
Timeline & Expected Recovery Course
About 73% of patients have another headache within 48 hours after leaving the emergency department.
A migraine attack commonly lasts 4 hours to 3 days. A tension-type headache may last 30 minutes to 7 days.
After treatment, about two to three in ten people have no pain at two hours. More than half get some relief.
A returning headache may be expected, but worsening or new symptoms change the picture and require reassessment.
Emergency Red Flags (When to Return Immediately)
Return to the emergency department immediately for any of these. This list is not exhaustive.
- A thunderclap headache that reaches full strength within seconds or minutes.
- Fever with a stiff neck, confusion, or being hard to wake.
- New weakness, numbness, vision changes, or trouble speaking.
- A headache that keeps worsening or feels completely different.
- Headache triggered by coughing, straining, lying down, or standing up.
- A new headache after age 50, or with cancer or a weakened immune system.
Reviewed September 3, 2026