A positive Mantoux Test, also known as a tuberculin skin test (TST), is determined by the size of the induration (raised, firm bump) that develops at the test site. The interpretation of a positive result varies depending on several factors, including the person's risk factors, clinical presentation, and local guidelines. In general, for individuals without specific risk factors, a Mantoux Test result with an induration size of 10 mm or greater is considered positive. However, for individuals at higher risk, such as those with compromised immune systems or recent TB exposure, a positive result may be defined as an induration size of 5 mm or greater. It is essential to consult with healthcare professionals familiar with the current guidelines in your region to accurately interpret the test results and determine the appropriate next steps based on the individual's specific circumstances. The interpretation of TB test results requires careful consideration of the person's medical history, risk factors, and clinical evaluation, and should always be done by healthcare professionals trained in TB management.