Getting Ready

Your appointment letter will explain if there's anything specific you need to do to prepare. You'll usually be asked to remove anything containing metal, such as jewellery, hair clips, or clothing with zips or poppers, and may be given a hospital gown to change into.

If you feel anxious about the scan, or have a fear of enclosed spaces, it's worth mentioning this to a doctor beforehand — they may be able to offer something to help you relax, or let you bring someone along for support.

During the Scan

You'll lie on a flat bed that moves slowly through the CT scanner, a large, ring-shaped machine, while it takes images from different angles. It's important to stay still throughout so the pictures come out clear. The scan itself is completely painless and typically takes between 10 and 30 minutes.

Some scans use a contrast dye, given as a drink, an injection, or occasionally an enema, to make certain areas of the body — such as blood vessels or the digestive system — show up more clearly. If you have the injection, you might feel warm, or notice an unusual sensation, but this passes quickly.

Weighing Up the Risks

CT scans use X-rays, so they involve a small amount of radiation exposure. The level used is kept as low as possible while still producing a clear image, and the potential slight increase in long-term cancer risk from a single scan is considered very small — doctors always weigh this against the benefits before recommending a scan, and can talk through any concerns you have beforehand.

It's important to tell the hospital if you're pregnant, since CT scans aren't usually recommended during pregnancy unless it's an emergency. Complications are otherwise rare — some people have an allergic reaction to the contrast dye, which can cause symptoms like weakness, sweating or breathing difficulty, so you may be asked to wait at the hospital for a short time after your scan if you've had contrast.

What Happens Next

A radiologist will study your images and write to the doctor who referred you for the scan. You may need a follow-up appointment to go through your results, and it's worth contacting the referring doctor if you haven't heard anything within around four weeks. They should explain what the results mean and whether any further tests are needed — don't hesitate to ask a healthcare professional if anything about your results isn't clear.