Non-Specific Urethritis and Sexually Transmitted Infections

Non-specific urethritis (NSU) is perhaps not very aptly names as there are a number of well-known causes for the condition which can be determined through testing and examination. One of the most common causes of non-specific urethritis is sexually transmitted disease, and in this article we look at which STIs (sexually transmitted infections) can cause NSU and how, as well as how these conditions can be effectively treated to alleviate the symptoms of NSU, and any potential complications of NSU caused by STIs.

STIs as causes of non-specific urethritis

Urethritis is essentially the painful inflammation of the urethra, a biological pipe through which we urinate. Urethritis is usually classed into either gonococcal or non-gonococcal (aka non-specific) urethritis. The former being cases attributable to the STI gonorrhoea, while the latter can be a consequence of any one of a wide range of different causes.


NSU can be caused by injury to the urethra or exposure to irritant chemicals like certain soaps for example, however the majority of the cases of NSU reported are actually caused by sexually transmitted infections. These infections can quite often affect the urethra because of the structure’s role in sexual intercourse, and the result is often the pain and discomfort of non-specific urethritis.

Chlamydia is a sexually transmitted disease which is thought to cause at least half of all cases of NSU in men and 40% of cases in women. Chlamydia is in fact one of the most prevalent STIs here in the UK, and is transmitted, like other STIs through unprotected sexual intercourse. Chlamydia is a bacterial infection which can be asymptomatic in 50% of male and as many as 80% of female cases. However when symptoms do present, urethritis is one of the most common, presenting with the distinctive burning during urination.

While chlamydia is perhaps the most common STI to cause NSU, it is far from the only one. A number of other sexually transmitted infections can cause urethral inflammation, and in many of the following examples the pathogen (infectious agent e.g. virus or bacterium) responsible for disease can be transmitted through oral and anal sexual contact as well as vaginal intercourse.

Mycoplasma is a class of bacteria which can potentially cause urethritis. There are many types of mycoplasma, but the type perhaps most commonly associated to NSU will be Mycoplasma genitalium, a species responsible for a sexually transmitted infection which often causes non-specific urethritis.

Certain viruses, most notably herpes simplex and adenovirus, can cause non-specific urethritis. Herpes simplex is the virus responsible for both genital herpes and cold sores, and there are in fact a number of different types of herpes virus which can have different effects on the body and different symptoms. Genital herpes is an STI which can cause non-specific urethritis, and this particular infection is quite often transmitted during oral as well as vaginal sex.

The adenovirus exists in dozens of sub-types which most often cause respiratory tract illnesses like tonsillitis, but because of the immense diversity of this particular type of virus, there are dozens of examples of other infections which can be attributed to the adenovirus. These include conditions like gastroenteritis, and genital infections leading to urethritis. Types 2, 37, and 8 are closely linked to non-specific urethritis, and infection with these subtypes can be sexually transmitted.

Trichomonas Vaginalis is a type of microorganism called a protozoan, a creature which usually resides within the urethra and can therefore often cause NSU. Trichomonas also causes a number of other symptoms, particularly an unpleasant discharge from either the vagina or penis. Trichomonas is less common than many other STIs that can potentially cause NSU.

As you can see from the above example, there are diverse STIs which can potentially cause NSU. Because of its location within our genitals, the urethra is particularly vulnerable to infection from these agents as it is often one of the first structures to make contact with an infected person’s tissues and fluids. This is also why many STIs will present with classic symptoms of urethritis.

Treatment and Complications of STI caused NSU

The usual treatment for non-specific urethritis is a course of antibiotics that is usually extremely effective in treating the condition and clearing up its symptoms within 2-3 weeks. The choice of antibiotics can be influenced by whatever STI is causing the NSU.

During the treatment period it is important to have sexual intercourse, even if your symptoms clear up quickly. During this time, which will be explained by your doctor, even though you might not have symptoms you will have traces of the infectious agent responsible for the condition within your urethra. This would allow for the further transmission of the disease and would contribute to the growing issue of STIs in the UK today. Moreover sex affect your ability to recover from more severe cases of urethritis.

In some cases the symptoms of NSU might not clear up within 2-3 weeks following treatment. In these instances, it is probably because of the underlying sexually transmitted infection persisting. Further testing would be needed to ensure that the right treatment is being provided to address the STI causing your urethritis. Further treatment should usually resolve the condition effectively.

There are cases where NSU can recur following an initially successful treatment. This can be attributed to a number of different factors, including, again, the underlying STI. In some cases treatment may kill enough pathogens to cause your urethritis to clear up, but leave some alive to cause a recurring infection. In other cases the relapse can be attributed to further infection through unprotected sexual contact. In most instances, however, the relapse is because a patient hasn’t followed their doctor’s instructions regarding the dosing regimen of their antibiotics. It is important that you follow the recommended dosage instructions to the letter, even if your symptoms clear up, as the regimen is designed to completely clear your system of infectious agents.

If your NSU is a caused by a sexually transmitted infection, it is extremely important that you inform previous sexual partners of the infection so that they can receive any testing or treatment that they might need. It may be embarrassing and difficult to do, but this step is essential to both preventing the further spread of the disease, and the long term health and safety of potentially infected people. NSU and its causative STIs can often be asymptomatic, particularly in women, and untreated infections can make their way up the urethra and into the reproductive system.

In women this can cause a serious condition called pelvic inflammatory disease, while in men it can cause a painful swelling of the testes and epididymis called epididymo-orchitis. Both of these conditions can potentially cause infertility, and PID can also affect future pregnancies in women. For these reasons making sure that anybody who needs treatment gets it is important.

Remember that while STIs are often a cause of non-specific urethritis, they aren’t exclusive causes of the disease. NSU can potentially be a result of injury to the urethra, or another infection, either way it is important that you seek medical advice if you do suffer from the symptoms of this condition to help you resolve it quickly and painlessly.

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