CT uses ionizing radiation, so a small theoretical cancer risk exists - and for a medically needed scan, the diagnostic benefit usually outweighs it clearly.
Scale matters: the FDA's dose table puts a chest x-ray at 0.02 mSv, a CT head at 2, a CT chest at 7, and a CT abdomen at 8 - which is why the question is fair, and why repeated scanning and children's scans get the most caution.
What to do
Common questions
Do CT scans cause cancer?
The honest answer: CT scans use ionizing radiation, and ionizing radiation at high enough doses raises cancer risk - but at the doses of an individual medically needed scan, the added risk is small and the FDA's framing is benefits versus risks, with the diagnostic benefit usually winning clearly. Scale helps: the FDA's dose table puts a chest x-ray at 0.02 mSv, a CT head at 2, a CT chest at 7, and a CT abdomen at 8 mSv - CT is hundreds of times a plain x-ray, which is why the question is fair to ask. The risk conversation concentrates on repeated scanning and on children, whose bodies are more sensitive. What to actually do: take the scan when a doctor says it is needed, ask whether a no-radiation alternative (ultrasound or MRI) could answer the same question, keep a list of your past scans, and decline only in conversation with your doctor, not unilaterally. Pymander, a free AI doctor available 24/7 by text, can help you weigh a specific scan order.