Condition guides
Every STD & STI, clearly explained
Anyone who is sexually active can get an STI, and most cause no symptoms at first. Each of these 18 guides covers the signs, the right time to test, what it costs, and how it's treated — in plain language, reviewed by our medical team.
Reported U.S. rate · per 100,000 (2023)
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Chlamydia 492.2
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Gonorrhea 179.5
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Syphilis (P&S) 15.8
Most STIs cause no symptoms, so reported cases undercount true infections, and rates vary widely by state. Source: CDC NCHHSTP AtlasPlus (2023).
18 of 18
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.
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Most reported Curable
Chlamydia
Chlamydia trachomatis
Chlamydia is the most commonly reported STI in the United States — 1.65 million cases in 2023, and most of them 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 is a bacterial infection that moves through stages — a painless sore, a distinctive rash, years of silence, and then, in untreated cases, irreversible damage to the heart, brain and eyes.
Test window 3–6 weeks
Manageable & preventable
Viral STIs
Managed with medication and, increasingly, prevented — the HPV vaccine and HIV PrEP. Early testing keeps them in check.
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Manageable
HIV/AIDS
Human immunodeficiency virus (HIV-1/HIV-2)
HIV is manageable now — but only if you know your status.
Test window 10–33 days -
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 4–6 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, and an estimated 13 million new infections occur each year.
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Manageable
Genital warts
Human Papillomavirus (HPV) types 6 and 11 — low-risk, non-oncogenic types that never cause cancer
Genital warts are caused by low-risk HPV types 6 and 11 — not the cancer-causing strains.
Vaccine-preventable
Viral hepatitis
Liver infections spread through sex or blood. Hepatitis A and B are vaccine-preventable; hepatitis C is now curable.
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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 transmitted 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 is a bloodborne liver infection that silently damages the liver for decades — but it is now curable with a short course of pills.
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.
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Curable
Trichomoniasis
Trichomonas vaginalis
Trichomoniasis is the most common curable non-viral STI in the United States — caused by a single-celled parasite, present in an estimated 2 million people annually, and silent in roughly 70% of those infected.
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 — called "crabs" because of their hooked, claw-like front legs — are tiny parasitic insects that cling to coarse body hair and spread almost exclusively through close sexual contact.
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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 completely curable skin infestation caused by a microscopic mite that burrows into the top layer of skin and causes an intensely itchy rash — classically worst at night.
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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 distinctive small, dome-shaped bumps with a characteristic 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.
The trend
The big three, tracked since 2020
Chlamydia, gonorrhea and syphilis are the three reportable STIs the CDC tracks nationally. The picture is mixed — not a single rising line — which is exactly why screening, not headlines, is what protects you.
Reported STD rates in the U.S. over time (per 100,000)
Chlamydia ▼ 1% vs 2022Between 2020 and 2023 in the U.S., chlamydia has risen from 476.7 to 492.2 per 100,000 (3%), gonorrhea has fallen from 204.5 to 179.5 per 100,000 (12%), and P&S syphilis has risen from 12.6 to 15.8 per 100,000 (25%).
The 2020 dip reflects reduced pandemic-era screening, not lower transmission. Source: CDC NCHHSTP AtlasPlus.
Editorial standards and sources
Reviewed by EasySTD Editorial Team, Health Writers & Researchers · Updated
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 →
4 Sources
Data & references
- CDC — Sexually Transmitted Infections (STIs) https://www.cdc.gov/sti/
- CDC NCHHSTP AtlasPlus — surveillance data https://www.cdc.gov/nchhstp/atlas/
- CDC — STI Treatment Guidelines, 2021 https://www.cdc.gov/std/treatment-guidelines/
- WHO — Sexually transmitted infections (STIs) https://www.who.int/news-room/fact-sheets/detail/sexually-transmitted-infections-(stis)
This page is educational information, not medical advice or a diagnosis. If you have symptoms or a possible exposure, speak with a clinician or get tested.