Guide

No—an A1C blood test doesn’t need fasting, so you can eat normally unless your visit includes other labs that do.

Most abdominal ultrasound bookings ask for no food for 6 hours, since an empty stomach and a full gallbladder can make the pictures clearer.

Most chest-wall echocardiograms let you eat and drink as usual; fasting is mainly for transesophageal scans and some stress studies.

Fasting depends on the exam: many upper-abdomen scans ask for 8–12 hours without food, while pelvic scans often ask for water and a full bladder.

No, fasting isn’t required for an ANA blood test, unless your blood draw includes other tests that call for it.

Fasting depends on the tests ordered: many annual panels don’t require it, but cholesterol and fasting glucose checks often do.

Most TB skin and blood tests don’t require fasting, so you can eat and drink as usual unless your visit includes other lab work.

Most apple juice lists 0 mcg of vitamin D unless the product is fortified, so the Nutrition Facts panel is the only sure check.

No—most urine drug tests don’t require fasting, so you can eat as usual unless the ordering clinic gives different instructions.

Most people don’t need to fast for an A1C test, since it reflects longer-term blood sugar, not the meal you ate today.