Lab test results may be positive, negative or inconclusive and are interpreted based on the condition being tested for, claims WebMD. Patients should discuss all test results with their doctor.
Blood test results that come back positive indicate that the condition or substance being tested for is present, explains WebMD. A positive result may also show that the substance being tested for is lower or higher than it should be. Test results that come back negative show that the condition or substance being tested for is not present. Negative results may also show that the substance the test is looking for is present in a normal amount.
Blood tests may also come back inconclusive, according to WebMD. This indicates that blood tests are not clearly negative or positive. For instance, if a test is measuring how many antibodies are present in the blood, the test may not clearly show that the antibodies are high enough to show there may be an infection. It is also possible that a test may come back as a false positive or negative. There are also blood tests that are more specialized and look for specific substances. These tests are different than general blood tests and are ordered by a doctor when suspecting certain conditions.