Condition library
STD & STI Conditions, Explained
Symptoms, the testing window, cost and treatment for every STD and STI we cover, in plain language, from chlamydia to HIV.
Curable with antibiotics
Bacterial STIs
The most common, and the most curable. A short course of antibiotics clears them, but they're frequently silent, which is exactly why testing matters.
- Most reported Curable
Chlamydia
Chlamydia trachomatis
Chlamydia is the most reported STI in the United States, 1.65 million cases in 2023, and most were invisible.
Test window 1–2 weeks - Curable
Gonorrhea
Neisseria gonorrhoeae
Gonorrhea is the second most reported STI in the United States, and it's in a race against our antibiotics.
Test window 1–2 weeks - Curable
Syphilis
Treponema pallidum
Syphilis moves through stages: a painless sore, a distinctive rash, years of silence, and then, untreated, irreversible damage to the heart, brain, and eyes.
Test window 3–6 weeks - Curable
Mycoplasma genitalium
Mycoplasma genitalium: a cell-wall-lacking bacterium, distinct from Mycoplasma hominis, making it intrinsically resistant to all beta-lactam antibiotics
Mycoplasma genitalium (MG) is an emerging bacterial STI with a catch: the antibiotics most people know don't work on it.
- Curable
Nongonococcal urethritis (NGU)
Urethritis not caused by gonorrhea (multiple causes. Chlamydia trachomatis, Mycoplasma genitalium, and others)
Nongonococcal urethritis (NGU) is inflammation of the urethra not caused by gonorrhea.
- Curable
Chancroid
Haemophilus ducreyi, a gram-negative bacterium
Chancroid, caused by the bacterium Haemophilus ducreyi, produces painful genital ulcers and tender, swollen lymph nodes in the groin.
- Curable
Lymphogranuloma venereum (LGV)
Chlamydia trachomatis serovars L1, L2, or L3
Lymphogranuloma venereum (LGV) is an aggressive form of chlamydia caused by more invasive strains of Chlamydia trachomatis.
- Curable
Granuloma Inguinale (Donovanosis)
Klebsiella granulomatis (formerly Calymmatobacterium granulomatis)
Granuloma inguinale (donovanosis) is a rare bacterial STI caused by Klebsiella granulomatis.
Manageable & preventable
Viral STIs
Managed with medication and, increasingly, prevented, the HPV vaccine and HIV PrEP. Early testing keeps them in check.
- Manageable
HIV/AIDS
Human immunodeficiency virus (HIV-1/HIV-2)
HIV is manageable now, but only if you know your status.
- Manageable
Genital Herpes
Herpes simplex virus (HSV-1 and HSV-2)
Genital herpes is one of the most common, and most misunderstood, STIs in the world.
Test window 4–16 weeks (antibody); swab a sore - Most common
HPV
Human Papillomavirus (HPV), a double-stranded DNA virus; 200+ types; ~40 infect the anogenital tract
HPV (human papillomavirus) is the most common STI in the United States: about 43 million Americans had an active infection in 2018, with an estimated 13 million new infections a year.
- Manageable
Genital warts
Human Papillomavirus (HPV) types 6 and 11: low-risk, non-oncogenic types that never cause cancer
Genital warts come from low-risk HPV types 6 and 11, not the cancer-causing strains.
- Curable
Mpox
Monkeypox virus (Orthopoxvirus)
Mpox, caused by the monkeypox virus, spreads mainly through close skin-to-skin contact, including intimate and sexual contact.
Vaccine-preventable
Viral hepatitis
Liver infections spread through sex or blood. Hepatitis A and B are vaccine-preventable; hepatitis C is now curable.
- Manageable
Hepatitis B
Hepatitis B virus (HBV), a DNA virus of the Hepadnaviridae family
Hepatitis B is a vaccine-preventable liver infection caused by a DNA virus spread through blood, body fluids, sex, and mother-to-child contact at birth.
Test window 3–6 weeks - Curable
Hepatitis C
Hepatitis C virus (HCV), an RNA virus of the Flaviviridae family; 6 major genotypes (1a and 1b most common in the U.S.)
Hepatitis C silently damages the liver for decades, but it's now curable with a short course of pills: an 8–12 week regimen of direct-acting antivirals cures more than 95% of people.
Test window 8–11 weeks - Curable
Hepatitis A
Hepatitis A virus (HAV): a non-enveloped, single-stranded RNA virus of the family Picornaviridae
Hepatitis A is a vaccine-preventable liver infection caused by the hepatitis A virus (HAV).
Treatable infestations
Parasitic & skin infections
Sexually transmissible parasites and skin infections: uncomfortable, but all straightforward to treat.
- Curable
Trichomoniasis
Trichomonas vaginalis
Trichomoniasis is the most common curable non-viral STI in the United States: a single-celled parasite, present in an estimated 2 million people, and silent in roughly 70% of them.
Test window 1–4 weeks - Curable
Pubic lice (crabs)
Pthirus pubis: the pubic or crab louse, a parasitic insect; a distinct species from head lice (Pediculus humanus capitis) with different biology, habitat, and treatment requirements
Pubic lice ("crabs," named for their hooked, claw-like front legs) are tiny parasitic insects that cling to coarse body hair and spread almost entirely through close sexual contact.
- Curable
Scabies
Sarcoptes scabiei var. hominis, a microscopic parasitic mite (0.3 mm) that burrows into the outermost layer of human skin to live and reproduce
Scabies is a fully curable skin infestation caused by a microscopic mite that burrows into the top layer of skin, causing an intensely itchy rash that's classically worst at night.
- Curable
Molluscum contagiosum
Molluscum contagiosum virus (MCV), a poxvirus; 4 subtypes; MCV-1 most common overall; MCV-2 most common in sexually transmitted adult cases
Molluscum contagiosum is a contagious poxvirus skin infection that produces small, dome-shaped bumps with a telltale central dimple.
No conditions match.
Symptom overlap
Same symptoms, different infections
Many STIs share the same handful of signs, and the same infection can look different from one person to the next. Most are often symptomless altogether: which is exactly why a test, not a symptom, is the only way to be sure. Use this to orient, then open a guide for the specifics.
common sign not typical A guide, not a diagnosis: symptoms vary widely, overlap, and are frequently absent. For anything you're worried about, open the condition guide or get tested.
Still not sure what you're looking at? Use the guided symptom checker for a personalized starting point, then test to be sure.
Treatment at a glance
How each one is treated
Most STIs are cured with a short course of medicine, and the rest are very manageable. Pick an infection to see the CDC-recommended regimen, the option if you're allergic to penicillin, what's safe in pregnancy, and roughly what it costs, so you know what to ask your provider for.
These are the CDC's recommended regimens shown for information, not a prescription or a dose to take on your own. A clinician confirms the diagnosis, checks allergies and interactions, and prescribes the right treatment. Never use leftover or someone else's antibiotics.
Four things that hold for almost every STI
Treat partners too
Getting treated while your partner isn't is the top cause of reinfection. Many states allow Expedited Partner Therapy so they can be treated without their own visit.
Wait 7 days
For the curable STIs, don't have sex until 7 days after treatment and until partners are treated, and until symptoms clear.
Retest in 3 months
Reinfection is common, so the CDC recommends re-testing about 3 months after treatment for chlamydia, gonorrhea and trich.
Finish the full course
Take every dose even if you feel better fast. Stopping early can leave infection behind and drive resistance.
Already treated? Get your safe-to-have-sex and retest dates, or read how long treatment takes to work.
Editorial standards and sources
Medically Reviewed & Fact-Checked · Updated
Reviewed by EasySTD Editorial Team
Compiled and checked by EasySTD's editorial team against CDC and public-health sources. This is educational information, not a substitute for advice from a licensed clinician. Our editorial guidelines →
10 Sources
Data & references
- CDC: Sexually Transmitted Infections (STIs)https://www.cdc.gov/sti/
- CDC: STI Treatment Guidelines, 2021https://www.cdc.gov/std/treatment-guidelines/
- CDC NCHHSTP AtlasPlus: surveillance datahttps://gis.cdc.gov/grasp/nchhstpatlas/main.html
- CDC: Sexually Transmitted Infections Surveillancehttps://www.cdc.gov/sti-statistics/
- U.S. Preventive Services Task Force: STI screening recommendationshttps://www.uspreventiveservicestaskforce.org/uspstf/topic_search_results?topic_status=P&category%5B%5D=15
- CDC: Which STI Tests Should I Get?https://www.cdc.gov/sti/prevention/index.html
- CDC: HPV Vaccinationhttps://www.cdc.gov/hpv/
- CDC: Pre-Exposure Prophylaxis (PrEP) for HIV Preventionhttps://www.cdc.gov/hiv/risk/prep/
- WHO: Sexually transmitted infections (STIs)https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)
- MedlinePlus (NIH): Sexually Transmitted Infectionshttps://medlineplus.gov/sexuallytransmitteddiseases.html