Among the number of reasons why people are worried about getting an STD test performed is that they fear it will be embarrassing or require uncomfortable swabbing. Thanks to significant improvements in testing technology, many STDs can be detected via a blood or urine test. Urine tests are primarily used to detect chlamydia. Testing chlamydia requires testing for the antibodies of the chlamydia bacteria Chlamydia trachomatis with a blood test using a small sample of blood. Although chlamydia is not a blood-borne disease, the body creates antibodies to fight off various diseases and infections, which are found in the blood. Although the test detects the presence of chlamydia antibodies, these antibodies could be the result of a previous chlamydia infection and would result in a false positive.