What is the difference between STI (sexually transmitted infection) and STD (sexually transmitted disease)? STI is an infection, and STD is a disease. The point at which you develop symptoms is when an STI becomes an STD.
Does it matter which term is used? No. But, if you are sexually active, you need to know when to get tested as well as recognize what symptoms may occur. Learning this information will help you protect your sexual health.
Infection or disease?
All STDs start as STIs.
STIs and STDs are not the same, but the medical community often uses these acronyms interchangeably. STD is sometimes used for both. STI is the most accurate because most sexually transmitted illnesses are infections without symptoms, and some, like human papillomavirus (HPV), can clear up on their own.
STIs are infections caused by bacteria, parasites, or viruses -- more than 30 types -- and transmitted from person to person during sexual contact (via penis, vagina, mouth, or anus) or contact with blood -- as when you share needles to inject drugs. If you are pregnant, you can pass the infection to your baby. STIs, such as chlamydia and gonorrhea, often have no symptoms. If you remain without symptoms and continue to be sexually active, you can spread the STI – and increase the chance of developing an STD. Untreated STIs can lead to serious complications.
Once you develop symptoms, the STI is an STD.
Millions of new STIs occur annually in the United States (U.S.). In 2018, according to CDC estimates, there were almost 68 million existing and new STIs. In the U.S., for every five people, one has an STI – that’s 20% of the population! Getting tested is the only way to know if you have an STI.
STI and STD Testing
CDC recommends testing for STIs if you are sexually active.
Have an honest conversation with your healthcare provider (HCP) about your sexual activity to determine what tests are recommended. Regular testing and treatment can slow or stop the spread of STIs and STDs.
For many STIs – such as chlamydia and gonorrhea -- testing is the only way you know you have it. Left untreated, these STIs may develop into STDs and cause serious complications.
Untreated chlamydia can cause pelvic inflammatory disease (PID) in women. Untreated gonorrhea can cause PID in women, and if you are pregnant, you can pass the infection to your baby, which can cause blindness, joint infections, or a blood infection. Untreated gonorrhea in men can cause epididymitis – swelling or pain in the back of the testicle in the coiled tube (epididymis) that stores and carries sperm. Getting diagnosed and treated right away can reduce the risk of complications.
If you are sexually active, getting tested, even when you have no symptoms, is essential for your sexual health. You should also be aware of the symptoms that STDs may cause.
If you develop symptoms like these, see your healthcare provider (HCP) as soon as possible.
- Painful or burning urination
- Sores, bumps, or warts on the vagina, penis, or anus
- Unusual discharge from the penis or vagina
- Unusual vaginal bleeding
- Pain during sex
- Sore, swollen lymph nodes
- Lower abdominal pain
- Rash over the trunk, hands, or feet
The more information you have, the better you can protect yourself and your partner. Getting an early diagnosis and treatment for an STD can prevent long-term complications.
There are treatments for STIs and STDs. Your HCP can help you with a diagnosis and appropriate treatment.
Antibiotics - can cure most bacterial-caused STIs.
Antivirals – treat STDs caused by a virus. There is no cure for viral STDs – antivirals can help to control the symptoms.
Getting diagnosed and treated is critical to your sexual health.
If you have not had sex or are currently uninfected, choosing to prevent STIs can keep you and your partner safer.
Prevention of STIs
Sexual health affects your physical, emotional, and mental well-being. It is vital for you to know the facts and use information and resources to keep yourself safe.
There are ways to prevent STIs.
Don’t have sex. Not having sex is called abstinence, and it is the most reliable way to prevent an STI. Abstinence includes no oral, anal, or vaginal sexual activity.
Have one uninfected partner in a long-term relationship. You only have sex with each other – neither are infected nor have sex with anyone else. This is a reliable way to prevent STIs. This method is also called mutual monogamy.
Wait to have sex with a partner until you have both tested negative for STIs.
Use latex condoms – new ones – correctly every time you have sex. Remember that neither birth control pills nor intrauterine devices (IUDs) prevent STIs.
Get vaccinated before sexual exposure for hepatitis A, hepatitis B, and HPV.
Use preexposure prophylaxis (PrEP) for HIV prevention. Talk to your HCP about this medication. You will need to test negative for HIV and do regular bloodwork.
Communicate with your partner before you have sex and agree to have safer sex to protect you. These conversations can feel uncomfortable but may keep you unharmed.
STIs and STDs are not the same, but these acronyms are often used interchangeably. Every STD started as an STI. No matter the term – STI or STD – if you are sexually active, now you know what it means. Knowledge is power.
If you think you or a partner might have an STI talk to your HCP right away and ask to get tested. Understanding sexual health allows you to make good decisions now and in the future.
Millions of new STIs occur annually in the United States (U.S.). In 2018, according to CDC estimates, there were almost 68 million existing and new STIs.
STIs are common. Knowing how to protect yourself from STIs, when to see your HCP for testing and treatment, and how to maintain your sexual health is significant.
Sexual health is important. Sexual health affects your physical, emotional, and mental well-being. It is essential for you to know the facts and use information and resources to keep yourself safe.
World Health Organization (WHO). Sexually Transmitted Infections
Mayo Clinic. Sexually Transmitted Diseases
Urology Care Foundation. What are Epididymitis and Orchitis?
Tulane University. STI vs. STD