Do You Need Fasting Before a CT Scan? When and Why

Many patients feel confused when they are told to do fasting before a CT scan. Not all CT scans require fasting, but in some cases, it is very important.

When Is Fasting Required?

Fasting is usually required when a CT scan with contrast is planned, especially for:

• CT Abdomen

• CT Pelvis

• CT Whole Abdomen

• CT Angiography

In these cases, patients are advised to not eat or drink for 4–6 hours before the scan.

Why Is Fasting Needed?

Fasting helps to:

• Reduce the risk of nausea or vomiting after contrast injection

• Improve image quality by reducing stomach and bowel contents

• Ensure better absorption and distribution of contrast dye

• Lower the chance of complications

When Is Fasting NOT Required?

Fasting is usually not needed for:

• CT Brain

• CT Chest (Plain)

• CT Spine

• CT Bone scans

Important Patient Tips

• You may drink small sips of water, unless told otherwise

• Continue regular medicines unless your doctor advises stopping them

• Diabetic patients should inform the radiology staff in advance

Conclusion

Fasting before a CT scan depends on the type of scan and use of contrast. Always follow your doctor’s or radiology department’s instructions for a safe and accurate CT scan.