A head CT scan for migraines involves exposure to a certain amount of ionizing radiation, which is generally considered low but not negligible. Typically, the radiation dose from a single head CT scan ranges roughly between 1 to 2 millisieverts (mSv). This level is significantly higher than that of a standard chest X-ray but still relatively low in the context of medical imaging.
To put this into perspective, natural background radiation exposure averages about 3 mSv per year for most people. So, one head CT scan delivers roughly the equivalent of several months’ worth of natural background radiation. The exact dose can vary depending on the specific machine settings and protocols used by the imaging center.
The reason doctors sometimes order a head CT scan when evaluating migraines is to rule out serious underlying conditions such as bleeding, tumors, or structural abnormalities that might mimic or contribute to headache symptoms. However, because migraines themselves are usually diagnosed clinically without imaging unless there are unusual features or “red flags,” routine use of CT scans for migraine evaluation is not always recommended.
Radiation from CT scans comes from X-rays passing through your body and being detected by sensors to create detailed images. While this ionizing radiation has enough energy to potentially cause cellular damage at high doses or with repeated exposures over time, modern scanners use optimized low-dose techniques specifically designed to minimize unnecessary exposure while maintaining image quality.
Children and young adults are more sensitive to radiation effects than older adults; therefore, physicians carefully weigh risks versus benefits before ordering brain CTs in younger patients with headaches.
In summary:
– A typical **head CT scan exposes you to about 1–2 mSv** of ionizing radiation.
– This dose is **low but higher than everyday background levels**.
– The test helps detect serious causes behind headaches but isn’t routinely needed for common migraine diagnosis.
– Modern scanners use **low-dose protocols** tailored for safety.
– Doctors consider patient age and clinical situation before recommending a head CT due to cumulative lifetime risks associated with repeated exposures.
If you have migraines without unusual neurological symptoms like weakness or vision changes, your doctor may suggest other evaluations first since MRI scans do not involve ionizing radiation and provide better soft tissue detail compared with CT scans. But if urgent assessment for stroke or bleeding is needed—especially after sudden severe headache onset—a quick head CT remains invaluable despite its small amount of radiation exposure.