What is malaria?

Malaria is a disease that occurs when blood is infected by parasites that are passed on through mosquito bites. There are five different types of malaria-causing parasites that can affect humans. Malaria has been mostly wiped out in the United States but is still a serious threat to human life in many parts of the world. It is a threat not only to those living in countries where it is common, but to anyone traveling to these areas. This means malaria can be rapidly spread even in areas where it is not usually found.

How common is malaria?

Malaria is a worldwide problem. With the number of people traveling throughout the world, it continues to be a risk, even in countries where it does not commonly occur.

Malaria is very common in developing countries and areas with high humidity and warm but moderate temperatures. Areas where malaria is most common include:

  • Parts of Central and South America
  • Haiti
  • The Dominican Republic
  • Africa
  • Eastern Europe
  • South and Southeast Asia
  • The South Pacific

The deadliest types of malaria are most common in Africa.

Who can get malaria?

People who can get malaria include those who are:

  • Exposed to a mosquito that is infected with the parasites that cause malaria;
  • Living in or traveling to one of the areas where malaria occurs;
  • Exposed to blood that is infected with malaria.

In addition, a fetus can become infected with malaria during pregnancy or birth if the mother is infected.

What causes malaria?

Malaria occurs when a mosquito infected with a malarial parasite bites a person and passes the parasite into his or her bloodstream. The parasite multiplies in the red blood cells, destroys them, and causes the person to become very sick.

An uninfected mosquito picks up the parasite when it bites an infected person. The parasite then multiplies in the mosquito and can be passed on to other people. It is easy to see how quickly many people can become infected.

What are the symptoms of malaria?

The symptoms of malaria include:

  • High fever
  • Chills
  • Shaking
  • Extreme sweating
  • Fatigue
  • Body aches and general discomfort
  • Headache
  • Muscle ache
  • Nausea
  • Vomiting

If the symptoms of malaria are not treated, the disease can lead to death.

Last reviewed by a Cleveland Clinic medical professional on 05/10/2017.


  • World Health Organization. International Travel and Health Accessed 5/17/2017.
  • Centers for Disease Control and Prevention. Malaria Accessed 5/17/2017.
  • National Institute of Allergy and Infectious Diseases. Malaria Accessed 5/17/2017.

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