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URL of this page: https://medlineplus.gov/infectiousdiseases.html

Infectious Diseases

Also called: Communicable diseases

Summary

What are infectious diseases?

Germs, or microbes, are found everywhere - in the air, soil, and water. There are also germs on your skin and in your body. Many of them are harmless, and some can even be helpful. But some of them can make you sick. Infectious diseases are diseases that are caused by germs.

What are the different types of germs that cause infectious diseases?

There are four main types of germs:

  • Bacteria are one-celled germs that multiply quickly. They may give off toxins, which are harmful chemicals that can make you sick. Strep throat and urinary tract infections are common bacterial infections.
  • Viruses are tiny capsules that contain genetic material. They invade your cells so that they can multiply. This can kill, damage, or change the cells and make you sick. Viral infections include HIV and the common cold.
  • Fungi are primitive plant-like organisms such as mushrooms, mold, mildew, and yeasts. Athlete's foot and yeast infections are common fungal infections.
  • Parasites are animals or plants that survive by living on or in other living things. Malaria and head lice are infections that are caused by parasites.

How can you get infectious diseases?

There are many different ways that you can get an infectious disease:

  • Through direct contact with a person who is sick. This includes kissing, touching, sneezing, coughing, and sexual contact. Pregnant people can also pass some germs along to their babies.
  • Through indirect contact, when you touch something that has germs on it. For example, you could get germs if someone who is sick touched a door handle, and then you touch it.
  • Through insect or animal bites.
  • Through contaminated food, water, soil, or plants.

What are the symptoms of infectious diseases?

Infectious diseases can cause many different symptoms. Some are so mild that you may not even notice any symptoms, while others can be life-threatening.

What are the treatments for infectious diseases?

There are treatments for some infectious diseases, such as antibiotic, antiviral, antifungal and anti-parasitic medicines. But for other infections, such as some caused by viruses, you can only treat your symptoms.

Can infectious diseases be prevented?

You can take steps to prevent many infectious diseases:

  • Get vaccinated
  • Wash your hands often
  • Pay attention to food safety
  • Avoid contact with wild animals
  • Practice safe sex (use a condom every time you have anal, vaginal, or oral sex)
  • Don't share items such as toothbrushes, combs, and straws

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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.