Sexually Transmitted Infections: Types, Transmission, Symptoms & Treatments

Lesson Transcript
Instructor: Artem Cheprasov

Artem has a doctor of veterinary medicine degree.

Sexually transmitted infections and diseases are typically passed from engaging in any type of sex with a person who is already infected. Explore different types of STIs and STDs and how they are transmitted, and learn about common symptoms and treatment options. Updated: 02/07/2022

Safe Sex

As if you haven't had enough of what I'm about to tell you in various high school and college classes: practicing safe sex is very important. It helps to prevent or minimize the chances that you will get a potentially painful and sometimes incurable disease.

That's what this lesson will be about - the important points about the different major types of diseases you can get from unprotected sex, what symptoms and signs to expect, and what the treatment options are.

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  • 0:01 Safe Sex
  • 0:29 Sexually Transmitted Infection
  • 1:33 Bacterial Sexually…
  • 4:06 Viral Sexually…
  • 6:29 Lesson Summary
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Sexually Transmitted Infections

Sexually transmitted infections (STIs), aka sexually transmitted diseases (STDs), are terms for a disease that is passed from an already infected person during sex.

Sexually transmitted diseases are transmitted through a wide variety of ways, including oral sex, vaginal sex, and anal sex. Some of these diseases can also be transmitted by coming into contact with blood that is deluged with the infectious agent.

What's very important to note is that you can get an STD from a person who is showing no signs or symptoms of the disease. Just because you can't see it, that doesn't mean it's not there! This is because the STDs are caused by microscopic - invisible to the naked eye - organisms. Namely, bacteria and viruses.

Despite all the warnings about having safe sex and screening for STDs, literally millions of people in the U.S. alone get STDs they've never had before.

Bacterial Sexually Transmitted Diseases

Let's first go over the different kinds of bacterial STDs these individuals may have caught.

The first major one is called chlamydia. This is the most common sexually transmitted infection in the U.S. and is caused by a bacterium called Chlamydia trachomatis. It's so common that it causes about four million new cases every year in the U.S. alone.

Chlamydia usually causes no symptoms. But again, that doesn't mean it can't be passed on to another person. Chlamydia can cause pain during urination, itching around the sexual organs of a person, and, critically, a problem called pelvic inflammatory disease in women. This problem can lead to infertility in women affected with chlamydia. This is why treatment with antibiotics, drugs that kill bacteria, is very important.

Other than chlamydia, an infection caused by the bacterium Neisseria gonorrhoeae, called gonorrhea, can also result in burning during urination. Additionally, gonorrhea causes a colorful discharge from the penis in men. It's usually a yellow, green, or white color. Oh, and if that's not bad enough for a man, gonorrhea can also cause the testicles to become very painful.

Women with gonorrhea also have pain during urination, and, if left untreated, gonorrhea can result in the inability to have children, just like chlamydia.

Speaking of children, gonorrhea (like many STDs) is an infection that can be passed from mother to child during childbirth. This is why if you have any of these signs or symptoms, make sure to get treated with antibiotics ASAP.

Finally, the last major bacterial STD I'd like to discuss is called syphilis. Syphilis is an STD caused by a bacterium known as Treponema pallidum. Syphilis is the STD that is famously known for causing a painless sore, called a chancre, at the point where the bacterium enters the body. The problem with syphilis is that it likes to disappear inside the body for sometimes decades on end without causing the person any trouble. However, when it reappears, it ends up causing everything from blindness to difficulty walking to dementia and eventually death. This is why the infection must be stopped right away with antibiotics, just like gonorrhea and chlamydia need to be.

Viral Sexually Transmitted Diseases

Well, enough of the bacterial stuff. It's time we move on to the viral STDs. For some, the names here may ring a bell more so than for the bacterial sections.

The most famous viral STD is known as HIV, or the human immunodeficiency virus, which ends up causing AIDS, a problem that results in immune system compromise. This is because HIV destroys white blood cells known as CD4+ T cells. When these cells are destroyed, a person is more susceptible to a secondary infection by another virus or bacterium. Unlike the bacterial stuff we discussed before, HIV/AIDS has no known cure. This is why combinations of different drugs, known as antiretroviral therapy, is used to stave off AIDS as a result of HIV.

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