STDs 101: An Introduction to Sexually Transmitted Diseases

Coupons for STD-screening discounts in April 2014 are available here.

It’s April, which for Arizonans means a gradual increase in temperature as we head toward summer. But at Planned Parenthood Arizona it also means that it’s time to focus on sexually transmitted diseases (STDs) in observance of STD Awareness Month. While we regularly provide information about sexual health with our monthly STD Awareness series, April is the time of year to fix the spotlight on sexually transmissible microbes and the infections they cause. April is also the time of year when Planned Parenthood Arizona offers coupons for discounted STD screening, so if you’ve been putting it off, now’s the time!

Symptoms of Sexually Transmitted Diseases

First, some basic facts. STDs can be transmitted through all sexual activities — vaginal, anal, or oral sex, as well as activities involving skin-to-skin contact. STDs are most commonly caused by viruses or bacteria, though they can be caused by other agents as well, including animals! Each STD is unique, with unique symptoms, but common symptoms include:

  • rashes, open sores, blisters, or warts in the genital area
  • swelling or tenderness
  • pus, bleeding, odor, or abnormal discharge
  • itching in the genital region
  • burning sensation during urination

It’s best not to focus too closely on symptoms, though — most people with STDs actually don’t experience any symptoms whatsoever! As they say in the biz, “The most common symptom of an STD is … no symptom.” For example, most people with herpes either have no symptoms or have mild symptoms that go unnoticed. Ten percent of males and 80 percent of females with gonorrhea don’t experience symptoms, and most people with chlamydia are asymptomatic. And HIV symptoms usually take a decade to show up. If you are, or have been, sexually active, you can’t assume that the absence of symptoms means you’re in the clear. To know for sure if you have an STD, the best thing you can do is to get yourself tested.

Preventing STDs

There are three main ways to avoid STDs: abstinence from all sexual activity, exclusive relationships in which partners have tested negative for STDs, and the correct and consistent use of barriers (like condoms and dental dams).

Barriers are usually made with latex, but there are alternatives, such as polyurethane, suitable for people with latex allergies. Condoms are the most well-known barrier method. They can be used in a wide variety of sexual activities, are inexpensive, and easy to find. The “female” condom (also called a receptive or insertive condom) is another option. It covers more surface area and is inserted into the vagina or anus. Lastly, dental dams are used as a barrier between the mouth and the vagina or anus.

More information about safer sex can be found at Planned Parenthood’s website. Other preventive measures you can take include receiving vaccinations for human papillomavirus (HPV) and hepatitis B virus.

Getting Tested for STDs

Planned Parenthood recommends that you receive STD screening if:

  • you have symptoms of an STD
  • you’ve had sex play with another person and did not use a condom, female condom, dental dam, or other barrier
  • any of your sexual partners have had an STD

STD testing can include a physical exam, as well as taking samples of blood, urine, saliva, discharge, tissue, or cells. If you have a cervix, you might need a pelvic exam. Many people are nervous or embarrassed about being screened for STDs, so if you’re in this category, you’re not alone. You can read this first-hand account of HIV testing at a Planned Parenthood Arizona location, which might put your mind at ease.

A Few Sexually Transmitted Diseases (and the Bugs That Cause Them)

Most sexually transmitted diseases are caused by viruses or bacteria. Some STDs are caused by other types of living organisms, such as protozoa or very tiny animals. We’ll review the different types of sexually transmitted pathogens and the infections they can cause below.

This scanning electron micrograph shows HIV particles (colored yellow) infecting a human T cell. Image: National Institute of Allergy and Infectious Diseases, National Institutes of Health

HIV particles (colored yellow) are shown infecting a human T cell. Image: National Institute of Allergy and Infectious Diseases, National Institutes of Health


STDs caused by viruses include HIV, herpes, and genital warts, and the viruses that cause them aren’t even technically living organisms — a virus consists of pieces of genetic information encased in a protein shell, which is able to infect a host cell. Viruses are the smallest of all sexually transmitted pathogens.

Some viral STDs, such as herpes and HIV, can’t be cured — but they can be treated as chronic conditions with medications that can slow down viral replication. If you have herpes, you can discuss with a doctor whether or not suppressive medications are right for you. And if you have HIV, antiretroviral drugs can significantly increase your lifespan and improve your quality of life.

Other viral STDs can be cleared by your immune system in most cases. For instance, most people infected with hepatitis B virus and human papillomavirus (HPV) make full recoveries, which means their immune system destroys the viruses and the infection goes away. However, in cases where the immune system fails, these viruses can cause chronic infections that have been linked to cancer (such as hepatitis, which is associated with liver cancer, and HPV, which is associated with throat cancer, cervical cancer, and anal cancer).

So far, there are no cures for viral STDs. You can be vaccinated against hepatitis B as well as the four major strains of HPV. Attempts to develop vaccines for herpes and HIV have been unsuccessful, although breakthroughs are being made in the treatment of HIV, with one patient even declared cured — his case, unfortunately, has not been replicated.

Neisseria gonorrhoeae, the bacteria species that causes gonorrhea, in a scanning electron micrograph. Image: National Institute of Biomedical Imaging and Bioengineering


Bacteria are single-celled organisms with relatively simple cell structures. Unlike viruses, bacteria can be killed with antibiotics. There are many different types of antibiotics, each targeting certain classes of bacteria; a single antibiotic will not kill all types of bacteria, so if you’ve taken an antibiotic for unrelated reasons, that doesn’t mean you don’t have to worry about asymptomatic STDs. (Be aware, also, that antibiotic-resistant strains of gonorrhea are out there, and they can be more difficult to treat.)

Some bacterial STDs can do long-term damage if not treated in time — and since they can be asymptomatic, it is especially important to be tested. Gonorrhea and chlamydia can spread to infect the fallopian tubes, uterus, and ovaries, resulting in pelvic inflammatory disease. Untreated, it can lead to infertility, ectopic pregnancy, and chronic pain. Gonorrhea and chlamydia can also develop into a condition called epididymitis, which is characterized by discomfort or pain in the scrotum, testicles, or epididymis — this condition can also affect fertility.

Syphilis can have severe long-term consequences. Its initial symptoms, if present, can be mild, and might include a painless sore that can appear three weeks to three months after infection. These sores contain a highly infectious liquid, making early-stage syphilis extremely contagious. If untreated, syphilis can remain dormant for years — in 15 percent of such cases, syphilis reaches the late stage, which can occur up to 20 years after initial infection. It includes severe damage to the nervous system, brain, heart, or other organs, and can be fatal.

Trichomonas vaginalis, in green, is much bigger than bacteria, in purple. Image courtesy of Antonio Pereira-Neves and Marlene Benchimol, Santa Ursula University, Rio de Janeiro, Brazil


Protozoan organisms are unicellular, like bacteria; unlike bacteria, their cell structures more closely resemble those of the so-called “higher” life forms such as animals and plants. They are much bigger than bacteria, as can be seen in the accompanying image.

Trichomoniasis is spread by vaginal or anal intercourse, direct vulva-to-vulva contact, and other activities that involve passing secretions from one partner to another. Up to half of trichomoniasis cases are asymptomatic, but symptoms disproportionally affect females and are very rare in males. When symptomatic, females might experience vaginal discharge (which may or may not have an unpleasant odor), spotting, and itching or swelling in the genital area.

Other protozoan STDs include giardiasis, amebiasis, and cryptosporidiosis, which are all caused by intestinal parasites. Intestinal parasites are usually transmitted by fecal contamination of food or water. Some pathogens, however, have low infectious doses, making their sexual transmission more likely. Oral contact with the anus, also called anilingus or rimming, is the primary means of the sexual transmission of these pathogens.

Pthirus pubis, the louse that can infect the pubic region. Image from the Public Health Image Library.

Pthirus pubis, the louse that can infest the pubic region. Image: Public Health Image Library


Most people don’t think of animals when they think of STDs, but scabies and pubic lice infestations are caused by tiny arthropods. Both are spread by prolonged intimate contact inherent to most sexual activities, but they can also be picked up from infected bedding.

Both scabies and pubic lice are treated with topical medications. While being treated, you can take actions to prevent reinfection, including vacuuming floors and cleaning rooms, and thoroughly washing all clothing, towels, and bedding in hot water. Your sexual partner(s) might also need to receive treatment.

Get Yourself Tested!

Because of the huge diversity of sexually transmitted pathogens and the variety of ways in which they are spread, STDs are very common among the sexually active population. And because it is so common not to have symptoms, it is important for any sexually active individual to be tested for STDs. Planned Parenthood clinics are affordable and nonjudgmental options for anyone seeking STD screening. This month, Planned Parenthood Arizona is offering coupons for discounted STD screening in observance of STD Awareness Month. You can also use this online tool to find the STD testing location nearest you.