Sexually transmitted diseases (STDs) are caused by sexually transmitted infections (STIs). They are spread mainly by sexual contact. STIs are caused by bacteria, viruses or parasites. A sexually transmitted infection may pass from person to person in blood, semen, or vaginal and other bodily fluids.


What is Syphilis?

What is Syphilis?

A highly contagious sexually transmitted bacterial infection characterized by painless sore on the genitals, rectum or mouth.
Urgent medical attention is usually recommended in severe cases by healthcare providers.

Symptoms & Reports

If you are experiencing new, severe, or persistent symptoms, contact a health care provider.
Symptoms vary as the disease progresses.

Primary stage

  • Enlarged lymph nodes near the groin.
  • Small, painless sores on the skin anywhere on the body, including inside the rectum and vagina.

Secondary stage

  • Small, reddish-brown sores on the skin
  • sores in the mouth, vagina, or anus
  • Fever
  • Swollen lymph glands
  • Weight loss
  • Hair loss
  • Headache and muscle aches
  • Extreme tiredness

Latent stage: No symptoms are noted for many years. But the person is highly contagious and progressing to the next stage.

Tertiary stage

  • Permanent organ damage
  • Death

HIV is spread through contact with genitals, such as during sex without a condom. This type of infection is called a sexually transmitted infection, also called an STI. HIV also is spread through contact with blood, such as when people share needles or syringes. It is also possible for a person with untreated HIV to spread the virus to a child during pregnancy, childbirth or breastfeeding.

Symptoms & Reports

The symptoms of HIV and AIDS vary depending on the person and the phase of infection.

Primary, also called acute HIV

Some people infected by HIV get a flu-like illness within 2 to 4 weeks after the virus enters the body. This stage may last a few days to several weeks. Some people have no symptoms during this stage.

Possible symptoms include:

  • Fever.
  • Headache.
  • Muscle aches and joint pain.
  • Rash.
  • Sore throat and painful mouth sores.
  • Swollen lymph glands, also called nodes, mainly on the neck.
  • Diarrhea.
  • Weight loss.
  • Cough.
  • Night sweats.

These symptoms can be so mild that you might not notice them. However, the amount of virus in your bloodstream, called viral load, is high at this time. As a result, the infection spreads to others more easily during primary infection than during the next stage.

Clinical Latent, also called chronic HIV.

In this stage of infection, HIV is still in the body and cells of the immune system, called white blood cells. But during this time, many people don’t have symptoms or the infections that HIV can cause.

This stage can last for many years for people who aren’t getting antiretroviral therapy, also called ART. Some people get more-severe disease much sooner.

When to see a doctor

If you think you may have been infected with HIV or are at risk of contracting the virus, see a healthcare professional as soon as you can.


What is HIV?

What is HIV?

Acquired immunodeficiency syndrome (AIDS), is an ongoing, also called chronic, condition. It’s caused by the human immunodeficiency virus, also called HIV.
HIV damages the immune system so that the body is less able to fight infection and disease.
If HIV isn’t treated, it can take years before it weakens the immune system enough to become AIDS.

Chlamydia and Gonorrhea

What is Chlamydia and Gonorrhea?

What is Chlamydia and Gonorrhea?

Chlamydia is caused by bacteria called Chlamydia trachomatis.

Chlamydia and gonorrhea are both common, highly contagious bacterial STIs. Both can be spread through unprotected sexual contact.

These infections are often found in the genitals, but they can also be found in the rectum and throat.

But they are not the same infection, and they are not caused by the same bacteria. Gonorrhea is caused by the Neisseria gonorrhoeae bacterium, also known as gonococcus.

Symptoms & Reports

Not all people infected with chlamydia or gonorrhea experience symptoms.

This can delay the time to diagnosis, as people who have the infection often don’t know until a test confirms the diagnosis.

Chlamydia symptoms

When symptoms are present, they can be different in men and women.

Common symptoms of chlamydia in females or other people with vaginas are:

  • Redness and swelling of the vagina
  • Vaginal itching and burning
  • Change in vaginal discharge
  • Painful urination
  • Feeling the need to urinate frequently
  • Painful sexual intercourse

In males or other people with penises, symptoms of chlamydia include:

  • Burning sensation during urination
  • Unusual discharge from the penis
  • Abdominal pain (particularly in the lower abdomen)
  • Pain or swelling of the testicles

Gonorrhea symptoms

Symptoms of gonorrhea also vary among men and women.

The most common symptoms of gonorrhea in females or other people with vaginas include:

  • Vaginal itching, burning, swelling, or redness
  • Increased or yellowish vaginal discharge
  • Painful or burning sensation when urinating
  • Urinating more frequently than usual
  • Bleeding between menstrual periods, or experiencing prolonged, heavier than usual menstrual periods
  • Painful intercourse
  • Abdominal or pelvic pain

In males and other people with penises, the most common symptoms of gonorrhea are:

  • Painful or burning sensation when urinating
  • White, yellow, or green discharge from the penis

Frequently Asked Questions

How common is condition?

Rare (Fewer than 200,000 cases per year in US)

Is condition treatable?

Treatable by a medical professional

Does diagnosis require lab test or imaging?

Requires lab test or imaging.

Time taken for recovery.

Can last several days or weeks.

How is condition transmitted?

Transmitted through sexual contact.

Common for ages 18-35

More common in males.


HIV is caused by a virus. It can spread through sexual contact, shooting of illicit drugs or use of shared needles, and contact with infected blood. It also can spread from parent to child during pregnancy, childbirth or breastfeeding.

HIV destroys white blood cells called CD4 T cells. These cells play a large role in helping the body fight disease. The fewer CD4 T cells you have, the weaker your immune system becomes.

How does HIV become AIDS?

You can have an HIV infection with few or no symptoms for years before it turns into AIDSAIDS is diagnosed when the CD4 T cell count falls below 200 or you have a complication you get only if you have AIDS, such as a serious infection or cancer.

How HIV spreads

You can get infected with HIV if infected blood, semen or fluids from a vagina enter your body. This can happen when you:

  • Have sex. You may become infected if you have vaginal or anal sex with an infected partner. Oral sex carries less risk. The virus can enter your body through mouth sores or small tears that can happen in the rectum or vagina during sex.
  • Share needles to inject illicit drugs. Sharing needles and syringes that have been infected puts you at high risk of HIV and other infectious diseases, such as hepatitis.
  • Have a blood transfusion. Sometimes the virus may be transmitted through blood from a donor. Hospitals and blood banks screen the blood supply for HIV. So this risk is small in places where these precautions are taken. The risk may be higher in resource-poor countries that are not able to screen all donated blood.
  • Have a pregnancy, give birth or breastfeed. Pregnant people who have HIV can pass the virus to their babies. People who are HIV positive and get treatment for the infection during pregnancy can greatly lower the risk to their babies.

How HIV doesn’t spread

You can’t become infected with HIV through casual contact. That means you can’t catch HIV or get AIDS by hugging, kissing, dancing or shaking hands with someone who has the infection.

HIV isn’t spread through air, water or insect bites. You can’t get HIV by donating blood.

Can chlamydia turn into gonorrhea?

No. Chlamydia and gonorrhea are different STIs caused by different bacteria. Though one infection cannot turn into another, people with one infection are more at risk for developing the other. For this reason, your provider may recommend testing for both infections at the same time, or testing for the other infection if the first is confirmed.

How common are chlamydia and gonorrhea?

Chlamydia and gonorrhea are the two most reported sexually transmitted infections in the United States. More than 2 million cases combined were reported to the Centers for Disease Control and Prevention (CDC) in 2019.