false negative

A false negative occurs when a test incorrectly indicates that a condition or presence of something is absent, even though it actually exists. For example, a medical test might fail to detect a disease in someone who is truly infected, leading the person to believe they are healthy when they are not. This can happen due to limitations in testing accuracy or timing. False negatives are important to identify because they can result in missed opportunities for treatment or necessary actions, emphasizing the need for reliable testing methods and sometimes additional follow-up tests.