A CT scan does use X-ray radiation, but a single scan advised for a genuine medical reason is not something to fear. The extra lifetime risk of cancer from one CT is very small - roughly in the range of 1 in a few thousand - while the information it gives can pick up a problem that would otherwise be missed and treated late. The radiation dose depends on the part scanned; a chest or head CT is much lower than a whole abdomen CT, and modern machines use low dose protocols. The sensible approach is simply not to repeat scans unnecessarily: ask your doctor whether an ultrasound or MRI can answer the same question, keep your previous reports and films so the same scan is not repeated, and always tell the technician if you are
pregnant or could be pregnant, as that is the one situation where CT is avoided unless unavoidable. If contrast dye is used, mention any
kidney problem,
diabetes medicines like metformin, or previous dye allergy, and drink plenty of water afterwards. So, no, it is not harmful in the way it is often described on the internet - if your treating doctor has advised it, please go ahead. If you want, share the reason it has been advised on a Practo consult (fee 500) or come to Synergy Multispeciality Hospital, Miraj, and I will tell you whether it is really needed in your case.