A bite from an animal can be very dangerous. Besides obvious injuries like tissue punctures and tears, bites can also introduce germs. Whether from a wild animal or from a pet, an animal bite - even one that seems minor - can cause a serious infection.

This is an intestinal infection. It's caused by a bacterium known as Clostridium difficile. We also call it "C. diff." It lives in the intestines of some people. For most who carry it, C. diff. doesn't cause problems. But it can spread to others, especially in places like hospitals and nursing homes. And when it infects someone new, it can grow out of control.

This infection is caused by a fungus known as Candida auris. We also call it "C. auris." It's an emerging threat around the world. It's spreading quickly, and it's very hard to fight with modern medicines.

This is a viral infection. It usually results in an itchy rash and mild sickness that lasts for five to 10 days. This virus spreads easily among children. In the past, contracting chickenpox was a routine part of childhood for most people. But a vaccine has made infections much less common.

This is one of the most common sexually-transmitted diseases. It's a problem for men and women. Medication easily cures it, but most people who are infected don't realize they have it.

This is a bacterial infection. It's caused by the cholera bacterium. It affects your digestive system. For some people, it causes severe diarrhea and other problems.

We've all experienced the sneezing, coughing, sore throat and fever of a common cold. But what, exactly, is a cold? And how do you fight it?

This is a swelling or an inflammation of the conjunctiva, a thin, clear layer of tissue in the eye. The conjunctiva covers the white part of your eye, and also the inner side of your eyelids.

This is a sexually-transmitted disease. It affects the genitals, rectum and throat in men and in women. It's cured with medication.

If your scalp itches, you may have a lice infestation. Lice are tiny insects that like to live in the hair on your head. They bite your scalp and feed on your blood. And they can spread from one person to another.

This viral infection affects the liver. It's a short-term infection that doesn't cause lasting harm. A vaccine has made hepatitis A infections rare in the United States.

This viral infection affects the liver. It causes the liver to swell, and damages liver cells. You can have a short-term hepatitis B infection that gets better without causing lasting harm. Or, you can have a chronic infection. This may cause permanent liver damage.

This is a viral infection that affects the liver. It can cause you to be mildly sick for weeks or months. But even after you feel better, the virus can stay inside your body. It can slowly harm your liver over many years.

This viral infection affects the liver. The virus that causes hepatitis D only infects you if you also have hepatitis B. If you get both infections at the same time, you may get better with no lasting harm. But when you have a chronic hepatitis B infection and then get hepatitis D, this is serious. It may lead to permanent liver damage.

This is a common viral infection. It causes small sores on or around your genitals, your buttocks or your anal area. They can also form around your mouth.

This is a common viral infection. It can cause small sores that we call "cold sores" or "fever blisters." Usually, these form on or around the lips or in the mouth.

This is a disease of your immune system. It begins as an infection by the human immunodeficiency virus, which we call "HIV." Over time, this virus can lead to acquired immunodeficiency syndrome. That's the syndrome we call "AIDS."

Good oral hygiene involves more than just keeping plaque away. You need to be aware of other dangers, too. One of the biggest is HPV. That's human papillomavirus. There are more than a hundred HPV viruses. Many affect the mouth and throat and genitals.

This is a group of viruses that infect your respiratory tract. Most people will be infected with a coronavirus at least once in their lifetime. Usually, symptoms are mild or moderate, and may seem like those of a common cold. But some coronaviruses can be very dangerous.

This common viral infection is sometimes called "the kissing disease." It can leave an infected person tired for weeks or months. Mononucleosis is most often seen in adolescents and in young adults.

This is an infectious disease commonly called "the flu." It targets your respiratory system. For some people, an influenza infection can be very serious.

This is a bacterial infection you get from a tick bite. It can spread through your body, causing flu-like symptoms. In some people, it can cause problems that last a long time.

This is a serious disease. It's caused by a single-celled parasite that lives and multiplies in your liver and bloodstream. It feeds on your red blood cells, destroying them. Malaria can make you very sick.

This is a disease you get from a virus. Measles isn't common. That's because most of us are vaccinated as children. But when an unvaccinated person is exposed to it, they can be infected. They can spread it to others.

This is a swelling of thin membranes called the "meninges." These three layers of tissue cover and protect your brain and your spinal cord. Meningitis is a serious condition. It can be life threatening.

This viral disease is related to smallpox. It's known as "monkeypox" because it was first found in colonies of monkeys. But the virus infects other animals and humans, too.

This type of infection is caused by a strain of bacteria that is resistant to many antibiotics. Because of this, it is hard to treat. A MRSA infection can cause serious complications. It can be life-threatening.

This set of symptoms develops in some people infected with COVID-19. It happens when different parts of the body become inflamed. It may develop days or weeks after becoming infected. It can be life-threatening.

This set of symptoms develops in some children infected with COVID-19. It happens when different parts of the body become inflamed. It may develop days or weeks after becoming infected. It can be life-threatening.

This is a disease you get from a virus. Mumps isn't common. That's because most of us are vaccinated as children. But when an unvaccinated person is exposed to it, they can be infected. They can spread it to others.

This rare brain infection is caused by an amoeba. We call it Naegleria fowleri. It lives in sources of warm fresh water, like lakes and rivers. It can also live in the soil.

This is a serious, painful infection that can spread quickly through soft tissues. If it's not treated properly, you can die from it.

This is an infection of the lungs. It can make breathing difficult. For some people, especially young children, the elderly and people who have a weak immune system, it can be very serious.

This syndrome affects a small percentage of people who have had a COVID-19 infection. It's a cluster of symptoms that can last for many months after your infection. Post COVID-19 syndrome can severely impact your life.

Pneumonia is an infection in one or both lungs. When you get it after surgery, we call it "postoperative pneumonia." It can be especially hard to fight off pneumonia when your body is healing from surgery. It can make your hospital stay much longer than expected. For some patients, it can be deadly.

This dangerous disease is caused by a virus. It can infect all mammals. The virus spreads through saliva, and attacks the brain and spinal cord. By the time symptoms appear, it's almost always fatal.

This is a virus that infects the lungs and airways. For most people an infection isn't dangerous. But for babies, the elderly, and for people who have a weakened immune system, infections can be severe.

This is an infection that causes red, circular rashes on your skin. Ringworm of the body can affect the skin anywhere except your scalp, your groin, the soles of your feet and your palms. But ringworm of the body is just one of many forms of ringworm infections. There are other, closely-related infections such as jock itch and athlete's foot that can affect other parts.

Scabies is an itchy skin rash caused by the microscopic scabies mite. It burrows into the skin, where it lives and lays its eggs.

This is a viral infection that usually affects older people. It makes your skin break out in a rash that can be very painful.

This is an infection caused by a parasite. It leads to swelling in your brain. Sleeping sickness can be very serious.

This common illness affects your digestive system. It's not really a flu. It's an inflammation of the lining of your intestines. Doctors often call it "gastroenteritis." Most people recover from it with no treatment.

This is a sexually transmitted disease. It's a serious problem for men and women. But it can be cured with medication.

This infection is caused by the tapeworm parasite. When you are infected, one or more tapeworms live and grow inside you. They can live in your intestines, and they can spread to other parts of your body. An adult tapeworm may live in the intestines for decades.

This is a serious illness also known as "lockjaw." It's a bacterial infection that causes muscles all over your body to tighten and spasm. It's a medical emergency.

This condition is an infection of the tonsils (the large lymph glands at the back of the throat). Tonsils normally help protect against infection, but they can become overwhelmed by viruses or bacteria. Tonsillitis occurs most often in children and rarely in adults.

This is an infection of the digestive system. It causes loose, watery poop. Traveler's diarrhea gets its name because it often strikes after visits to places with poor public hygiene.

This disease, most commonly a problem among people who live in developing countries, is a bacterial infection that usually attacks the lungs. It can also affect other parts of the body, such as the brain, spinal cord and kidneys. A full-blown, active case of tuberculosis can be deadly.

This is a bacterial infection. It's caused by the Salmonella typhi bacterium. It spreads easily between people.

This is a viral infection you get from a mosquito bite. For most people, it's not serious or dangerous. You can get it and not even know you have it. But for some people, it can be life-threatening.

This is an infection of the lining of your airways. It is highly contagious. It is most common in young children who have not been fully vaccinated and in people who have not received booster shots.

This is a viral infection. It is common in South America, and in sub-Saharan Africa. The virus that causes it is carried and spread by mosquitoes.

This viral infection is spread by mosquitoes. For most people, it's not serious or dangerous. You can get it and not even know you have it. But it can cause problems for a developing fetus. It can cause severe, permanent disabilities. It can be fatal.