What does the abbreviation R/O stand for in a medical context?

In a medical context, the abbreviation R/O stands for "Rule Out." This term is commonly used by healthcare professionals to indicate that a certain condition or diagnosis needs to be excluded based on the findings from a patient's evaluation or diagnostic tests. For example, if a physician suspects a patient might have a specific condition, they may decide to R/O that condition by ordering further tests or observations to confirm or negate the diagnosis. This approach is critical in clinical practice, as it helps ensure that the correct diagnosis is made and appropriate treatment can be administered, thereby improving patient outcomes.