Other causes include: 1  A fall against a hard surface in the seated position, such as a fall from a horse. 2  A direct blow to the coccyx, such as in contact sports.  Straining or dislocating the coccyx. This can happen due to poor posture while driving, or repetitive injury from sports such as rowing or cycling.
1 Positive test results also can mean that the amount of a substance being tested for is higher or lower than normal. 2  A negative test result means that the substance or condition being tested for was not found. false-negative test result may suggest that a person does not have a disease or condition being tested for when he or she does have it. For example, a false-negative pregnancy test result would be one that does not detect the substance that confirms pregnancy, when the woman really is pregnant.
Always Test Clean has assembled the most comprehensive list of what can cause a false positive drug test. Search a list of foods, medications and prescriptions that can cause a false positive drug test by name.The following is a list of medications, prescriptions and other things that can cause a false positive drug test cross referenced to the type of drug test you can expect to be at risk for passing a drug test.here are no major products that can cause a false positive drug test that begin with âJâ. K. 1  Klonopin â Contains Benzodiazepines. 2  Koalin Or Morphine Mixture â Can Cause False Positives For Opiates.