Understanding the Different Types of STDs: A Guide to the Basics

STDs fall into three main categories: bacterial, viral, and parasitic. Each behaves differently in the body, requires different treatment, and has different implications for long-term health. Understanding these distinctions is the foundation of informed sexual health decision-making.

• Bacterial STDs — chlamydia, gonorrhea, syphilis — are curable with antibiotics when caught early

• Viral STDs — HIV, herpes, HPV, hepatitis B — cannot be cured but can be effectively managed or prevented with vaccines

• Parasitic STDs — trichomoniasis, pubic lice, scabies — are treatable and curable

• Most STDs are asymptomatic for extended periods — testing is the only reliable way to know your status

• Different infections require different tests — a standard panel does not cover everything

Bacterial STDs

Bacterial STDs are caused by bacteria and are curable with targeted antibiotics. The defining challenge is that most are frequently asymptomatic, so many infections go undetected and untreated.

Chlamydia

The most commonly reported STD in the US. Up to 75% of infected women have no symptoms. Untreated chlamydia is a leading cause of Pelvic Inflammatory Disease and tubal factor infertility. Treatment: doxycycline (7 days) or azithromycin (single dose).

Gonorrhea

Frequently asymptomatic, particularly in women. Can infect the genitals, rectum, and throat. Rising antibiotic resistance is a significant public health concern — current treatment relies on injectable ceftriaxone, with resistance emerging. Treatment: intramuscular ceftriaxone (single dose).

Syphilis

Progresses through stages: a painless sore (primary), a rash on palms and soles (secondary), a symptom-free latent phase, and potentially serious organ damage in tertiary disease. Cases have more than doubled in the US since 2018. Treatment: penicillin G.

Mycoplasma Genitalium

More common than gonorrhea in many populations but absent from most standard panels. Causes urethritis in men and cervicitis or PID in women. Up to 70% asymptomatic. Complicated by high antibiotic resistance rates. Must be specifically requested for testing.

Viral STDs

Viral STDs cannot be eliminated from the body with current treatments. Goals of treatment are symptom management, reducing transmission risk, and preventing disease progression. Two viral STDs — HPV and hepatitis B — can be prevented through vaccination.

HIV

Attacks the immune system’s CD4+ T cells. Without treatment, progresses to AIDS. Modern antiretroviral therapy (ART) suppresses viral replication to undetectable levels, allowing normal life expectancy and preventing sexual transmission (U=U). PrEP is highly effective for prevention in HIV-negative individuals.

Herpes (HSV-1 and HSV-2)

Establishes lifelong latency in nerve tissue. Causes periodic outbreaks of blisters or sores. Many infections are asymptomatic. Antiviral therapy reduces outbreak frequency and transmission risk by 50–80% but does not eliminate the virus. An estimated 1 in 6 Americans aged 14–49 has genital herpes.

HPV

The most common STD globally. Low-risk strains cause genital warts; high-risk strains cause cervical, anal, penile, throat, and vulvar cancers. Most infections clear spontaneously. Gardasil 9 vaccine prevents infection with nine strains responsible for most HPV-related disease.

Hepatitis B

Transmitted sexually, through blood, and from mother to baby. 10% of adult infections become chronic, risking cirrhosis and liver cancer. A highly effective vaccine has been available since 1982. Chronic infection is managed with antivirals.

Hepatitis C

Primarily bloodborne; sexual transmission occurs particularly in certain practices. Causes chronic liver infection in most untreated cases. Modern direct-acting antivirals cure over 95% of chronic infections. No vaccine exists.

Parasitic STDs

Caused by single-celled parasites or small arthropods. All are treatable and curable.

Trichomoniasis

The most common curable STD globally. Up to 70% of infections produce no symptoms. When present, women experience frothy, foul-smelling discharge and itching. Increases HIV susceptibility. Treatment: metronidazole or tinidazole (single dose, both partners treated).

Pubic Lice

Parasitic insects infesting coarse body hair. Transmitted through close physical contact. Cause intense itching. Treatment: topical permethrin or malathion; wash clothing and bedding at high temperature.

Scabies

Caused by mites burrowing under the skin. Intense itching, especially at night. Transmitted through prolonged skin contact including sexual contact. Treatment: permethrin cream or ivermectin applied to entire body; all household contacts treated simultaneously.

Why the Type Matters

The type of STD determines the test needed, the treatment required, and the long-term management approach. A urine test for chlamydia will not detect herpes. An antibiotic for gonorrhea will not treat trichomoniasis. Getting the right tests for your specific risk profile, and understanding what they can and cannot detect, is essential for actually knowing your status.

Tips

• Know what your standard panel covers — most routine panels cover chlamydia, gonorrhea, HIV, and syphilis. Ask specifically what is and is not included.

• Request additional tests based on your risk — trichomoniasis, mycoplasma genitalium, herpes, and hepatitis require specific additional tests.

• Get vaccinated against HPV and hepatitis B — these are the only STDs with vaccines, and vaccination before exposure provides the most protection.

• Curable does not mean trivial — bacterial STDs cause serious complications when untreated. Curable means treatable, not harmless.

• Incurable does not mean unmanageable — HIV, herpes, and hepatitis B are all effectively managed with modern treatments.

Frequently Asked Questions

Are all STDs sexually transmitted?

All STDs can be transmitted sexually, but many have additional routes. HIV, hepatitis B, and hepatitis C transmit through blood and from mother to baby. Herpes can transmit through non-sexual skin contact. Scabies and pubic lice transmit through close physical contact including non-sexual contact.

Can you have more than one STD at the same time?

Yes. Co-infections are common. Having one STD generally increases susceptibility to others by disrupting normal protective barriers. Testing for multiple infections simultaneously is more efficient and clinically appropriate.

Do asymptomatic STDs still need treatment?

Yes. Asymptomatic infections are still active, still causing potential damage, and still transmissible. Treatment of asymptomatic infections is just as important as treatment of symptomatic ones.

How quickly after exposure can STDs be detected?

Chlamydia and gonorrhea: 1–2 weeks. Syphilis: 3–6 weeks. HIV (4th generation): 18–45 days. Herpes antibodies: 12–16 weeks. Testing before these windows may produce false-negative results.

Is there a single test that covers all STDs?

No. Each STD requires a specific test or sample type. Always ask specifically what a “full panel” includes at your provider — it varies significantly.

Get Tested Today

Knowing which STDs exist is the starting point. Knowing your own status requires testing. Fast, confidential testing for a full panel is available at sexual health clinics and online.

Related reading: The Most Common STDs in the US · Can You Have an STD With No Symptoms? · Rare STDs You’ve Never Heard Of · How Often Should You Get Tested?