Once you are well past surgery, follow-up visits often bundle several tests into a single day — a blood draw, a urine sample, a chest X-ray, and a CT scan that uses contrast. Grouping them saves you repeated trips to the hospital, but the first time it can be confusing to know what to do first and what to fast for.
The first thing to sort out is fasting. Each test has its own preparation. Urine tests and X-rays usually need no fasting, but a blood test measuring glucose or lipids, and a contrast-enhanced CT, often call for a few hours without food. Whether you may drink water, and how many hours ahead to stop eating, differ from one hospital's instructions to another — so follow the exact wording on your appointment message or leaflet. If you have lost it, call the booking desk the day before.
The contrast media used in CT travels through your blood vessels to make organs show up clearly. A warm flush through the body or a brief sensation of needing to urinate as it is injected is a common, normal reaction. Still, your kidney function (the creatinine and eGFR on your blood test), any history of contrast allergy, and whether you take diabetes medicine — metformin in particular — are things to tell the staff in advance. Drinking plenty of water before and after helps your body clear the contrast.
A few things make the day less tiring: your ID and hospital card, a list of the medicines you take, comfortable metal-free clothing, and a light snack and water to have as soon as the fasting tests are done. The order is often blood and urine first with the fasting CT later, but it varies, so asking the front desk "what order today, and how long will it take?" makes it easier to plan your day.
After the tests comes the wait for results. Blood results may come quickly, while a CT report can take a few days. Rather than dwelling anxiously until then, note your next appointment date and how you will get the results — clinic visit, app, or phone — to ease some of the worry.
This article is general information and does not replace your own medical care. Fasting times, whether contrast is used, and test preparation differ from person to person, so please follow your care team and your hospital's instructions.