The terms STI and STD are often used interchangeably, but they do not mean the same thing. An STI, or sexually transmitted infection, means that a virus, bacteria, fungus, or parasite has entered the body through sexual contact. An STD, or sexually transmitted disease, generally refers to a disease state that develops because of that infection.
It is important to know the difference between the two, as one may have an STI without having any symptoms. That is one reason the term STI has become more common in healthcare.
What Is an STI?
Sexually transmitted infections, or STIs, are infections that can be acquired through sexual intercourse. When there is an infection, this means that there is a virus, bacteria, fungus, or parasite in the body, although this does not always mean a person will feel sick or notice symptoms.
Most sexually transmitted infections do not cause symptoms, which means that people might already have an infection while being unaware of its presence.
Examples of infections commonly discussed as STIs include:
- Chlamydia
- Gonorrhea
- Syphilis
- Genital herpes
- Human papillomavirus (HPV)
- Trichomoniasis
- HIV
Some of these infections can be cured with appropriate treatment, while others can be managed with ongoing medical care.
What Is an STD?
An STD is a sexually transmitted disease. An STD, or sexually transmitted disease, generally refers to a disease that develops from a sexually transmitted infection and begins causing symptoms or other effects on the body.
For example, an infection may be present before a person develops noticeable signs or health problems. Once the infection begins causing a recognizable disease process, the term STD can be used. In everyday conversation, though, people and healthcare providers often use STI and STD to describe the same general group of conditions.
STI vs STD: What Is the Main Difference?
The simplest way to understand the difference is that an STI refers to the infection itself, while an STD refers to disease that develops as a result of that infection. Someone can therefore have an STI without having symptoms or a diagnosed disease.
This distinction is important because waiting for symptoms before getting tested can allow an infection to go unnoticed. Many STIs can remain asymptomatic or cause symptoms so mild that they are easy to miss.
Why Is “STI” Used More Often Today?
Healthcare and public health organizations increasingly use the term STI because it describes the infection at an earlier stage, including when symptoms are absent. The term also reflects the fact that someone does not need to feel sick before testing or treatment becomes important.
STD is still widely used and understood, especially by patients searching for testing or treatment. Both terms remain common, but STI is often considered the more medically precise term.
Does Having an STI Mean You Will Develop an STD?
No. Some infections will either be detected early enough or treated so that they do not lead to any illnesses, while there may be others that do not cause any symptoms despite being able to cause some effects on you and spread to other individuals.
What happens depends on the specific infection, whether it is treated, your overall health, and other individual factors. Early testing and appropriate treatment can reduce the likelihood of certain complications.
Can You Have an STI Without Knowing It?
Yes. Many STIs cause no symptoms or only mild symptoms, particularly early in an infection. That means you cannot reliably determine whether you have an STI based only on how you feel.
When symptoms do occur, they can vary depending on the infection. Possible signs can include:
- Unusual genital discharge
- Burning or discomfort during urination
- Sores, bumps, or rashes
- Itching and irritation in the genitals
- Pelvic pain
- Pain during intercourse
- Unexpected bleeding
These symptoms can also be caused by conditions unrelated to an STI, which is why testing and medical evaluation are important.
Is STI Testing Different From STD Testing?
When someone asks for an STD test or an STI test, they are generally referring to the same type of screening. Your provider will determine which infections should be tested for based on factors such as your age, symptoms, sexual history, recent exposures, and other risk factors.
Testing may involve blood, urine, or swab samples depending on the infection and the areas of the body that may have been exposed. There is no universal test that can test for all kinds of STIs.
When Should You Consider STI/STD Testing?
Testing does not have to be limited to times when symptoms are present. You may want to discuss screening with a healthcare provider if:
- You have a new sexual partner
- You or a partner have multiple sexual partners
- You had sex without a condom or another barrier method
- A condom broke or slipped
- Your partner has tested positive for an STI
- You have some symptoms that may be associated with the infection
- You worry about a recent sexual experience
- You have not been screened recently
- You want to discuss HIV or STI prevention
How often you should be tested depends on your individual circumstances, so your provider can help determine which tests are appropriate and how often screening makes sense.
Can STIs Be Treated?
Treatment depends on the infection. Some bacterial and parasitic STIs can be cured with appropriate medication, while viral infections generally cannot be eliminated from the body in the same way but can often be managed effectively.
An example is that of HIV, which can be controlled but not cured; herpes can be managed with the use of medication. Certain infections, such as hepatitis B and HPV infections, can be prevented with vaccines.
How Can You Reduce Your Risk?
Lowering your risk of an STI often comes down to a combination of practical habits and preventive care. That can include using condoms or other barriers, keeping up with recommended vaccines, testing at intervals that make sense for you, and talking with partners about sexual health.
For some people, prevention may also include medication. PrEP and PEP can help reduce the risk of HIV in different situations, while DoxyPEP may be considered for certain people who are at increased risk for some bacterial STIs.
STI or STD: Which Term Should You Use?
Either term will usually be understood. STI is often the technically correct term to use when referring to an infection that could be symptomatic or asymptomatic, but STD is still widely used by patients, healthcare providers, and websites.
What matters more than the terminology is knowing that an infection can be present without symptoms and that testing is available. If you are searching online for care, you may see clinics use both “STI testing” and “STD testing” because patients commonly search for both terms.
Take Care of Your Sexual Health With Circle Care Center
Regardless of whether you refer to STI testing or STD testing, your status is essential in making informed choices. At Circle Care Center, we have comprehensive sexual health services including STI/STD testing, STI/STD treatment, HIV prevention and management services.
Our healthcare providers are compassionate and affirming of the LGBTQ+ community and will help you decide what type of tests or prevention is right for you. If you are due for routine screening, concerned about a recent exposure, or simply have questions about your sexual health, request an appointment with Circle Care Center.