How long does it take to fast before a breath test?

Before a breath test, it is generally necessary to fast for 6-8 hours, and the specific time needs to be adjusted according to the testing items.

Breath test is commonly used for the diagnosis of diseases such as helicobacter pylori infection or lactose intolerance. Fasting can reduce the interference of food on the test results. The gastric emptying time is usually 4-6 hours, but some tests require stricter standards. For example, the carbon-13 urea breath test requires fasting for at least 6 hours, while the lactulose hydrogen breath test may need to be extended to 8 hours. During fasting, it is prohibited to eat any solid or liquid food, including water, chewing gum, etc., but some tests allow for a small amount of water to be consumed. High fiber foods, carbonated drinks, and antibiotics that may affect the results should be avoided 24 hours before the examination. Smoking and vigorous exercise may also interfere with the accuracy of the test, and specific requirements need to be confirmed with a doctor in advance. On the day of the inspection, it is recommended to bring medical records and wear loose clothing. If you experience symptoms of low blood sugar such as dizziness, you can inform medical staff to evaluate whether to adjust the testing time. After completing the test, it is necessary to eat easily digestible foods in a timely manner to avoid gastrointestinal discomfort caused by prolonged fasting. Long term use of hypoglycemic drugs or gastric acid inhibitors requires prior communication with a doctor regarding medication adjustment plans.