A breath test is a medical procedure used to analyze a person's breath for specific substances. It is commonly used to detect the presence of alcohol, as well as certain medical conditions like lactose intolerance or Helicobacter pylori infections. The test typically involves the individual exhaling into a device that measures the concentration of the target substance. The results from a breath test can provide quick and non-invasive insights into a person's health or behavior. For example, a high level of alcohol in the breath indicates recent consumption, while specific gases can signal digestive issues. This method is often preferred for its simplicity and speed.