The reference range may differ depending on your gender, age, medical history, and current condition, among other factors. If your test results are positive, you may have been infected with tuberculosis at some point in the past. A positive result does not necessarily mean that the infection is active. If your test results are negative, it’s possible that the infection isn’t present. If you receive unexpected test results, see your doctor right away. Depending on the findings of your examinations, your doctor may suggest more tests.