What Is a Penis Swab?

The term “penis swab” can refer either to a medical test performed to detect urinary tract problems and sexually transmitted diseases in men, or to the tool used in that test. There are few different ways to test for and detect these sorts of infections and diseases, but actually sampling or “swabbing” the cells from inside the penis is usually one of the most accurate as well as one of the fastest. The test itself is not usually pleasant, but it doesn’t take long and in most cases isn’t painful for long.

The physical penis swab is typically long, thin, and made of hard sterile plastic topped with a cotton tip, not unlike a common ear swab. It is designed to be inserted into the tip of the penis through the urethra. In most cases it is long enough that the doctor or medic performing the test can hold the end a safe distance from the penile tip with enough leverage to safely guide the swab in and out. When done correctly, the cotton top will collect urethral discharge and other cellular matter that is critical to making most diagnoses.

Swabs are usually designed to be disposable and they typically come individually packaged. Doctors and nurses will open each swab while wearing sterile exam gloves to make sure they do not contaminate the test site. Wiping the penile tip with a disinfecting wipe is also common practice. Any foreign substance, whether from the patient or the examiner, can invalidate test results.

Using a penile swab is usually somewhat straightforward, though care is required to avoid injury or excessive pain. The swab needs to go up the penis shaft by at least an inch (about 2.5 cm) in most cases. Once it has been inserted, the person performing the test will rotate it multiple times to make sure that cells are being collected. Patients are usually asked to refrain from urinating for at least two hours before the test, since urination can flush out many of the cells needed to make an accurate diagnosis.

When the swab is removed from the patient's body, it must usually be placed immediately in a sterile bag or container to be sent to a lab for testing. Lab technicians will then smear the collected cells onto slides and study them, usually under a microscope and sometimes with the help of dyes or stains.

Capturing and studying urethral cells is one of the most effective ways to diagnose problems and diseases that impact the urinary tract. Any time patients present with penile discharge, health care providers often order the swab test as a way of getting more information when it comes to what, exactly, is going on. The test is also routinely done on men suspected of having either gonorrhea or chlamydia, two highly contagious sexually transmitted diseases (STDs).

The swabbing process is generally unpleasant for most men, but it should not be extraordinarily painful. Extreme pain is often an indication that something has gone wrong: the swab may have been inserted too far, for instance, or it may have been pushed in with enough force to perforate the tissues or break the skin. It’s sometimes possible to purchase “at-home” swab kits to self-diagnose various STDs, but most experts don’t recommend this approach simply because of how easy it can be to inflict injury.

Sterile conditions are also really important. The moist tissues of the penis tend to be very susceptible to germs, bacteria, and other outside elements. Carefully washing the area with soap and water before beginning is usually a good idea; wearing gloves is also critical. The swab itself must also be kept clean and dry both before and after the procedure to ensure accurate results and prevent cross-contamination.