Skip to main content

Health library

Back to health library

What is malaria?

If you're planning a trip outside the country, find out if malaria is common where you're going. Medicines can protect you from the disease.

Malaria is a deadly disease that's spread to humans by female Anopheles mosquitoes. It is common in the tropics, where it often affects young people. Malaria causes more than 500,000 deaths annually—mostly among African children—according to the World Health Organization (WHO).

In the United States, most cases of the disease occur in either people who've traveled outside the country or people who have moved here from another country, says the Centers for Disease Control and Prevention (CDC).

The symptoms

The parasites that cause malaria usually begin causing symptoms between 10 days and four weeks of the mosquito bite. Symptoms occur only during an attack, when the red blood cells that carry malaria burst and release more parasites into the bloodstream. The symptoms may include:

  • Fever.
  • Shaking.
  • Chills.
  • Severe headache.
  • Vomiting.

If it's not treated, malaria can destroy so many blood cells that they block blood vessels in vital organs, such as the kidneys, liver, spleen and brain. As a result, malaria can cause coma, convulsions, anemia, kidney and liver failure, and death.

What can you do?

In rare cases, people have developed malaria after sharing needles with an infected person or receiving an infected blood transfusion. But most Americans get malaria after traveling to areas where the disease is common.

If you're planning a trip to one of these areas, see your doctor first. Medicines can protect you from malaria while you're traveling.

Watch out for mosquitoes

Even if you're taking medicine to prevent malaria, it's still a good idea to avoid mosquito bites. CDC advises that you:

  • Wear long-sleeved shirts, long pants, boots and socks, especially in the evening and in places where mosquitoes are most active.
  • Use insecticide sprays on exposed skin and clothing.
  • Put screens over windows or use mosquito nets.

Treating malaria

If you develop symptoms of malaria after traveling to a high-risk area, see your doctor right away. The doctor will check for malaria by taking a blood sample. If you have the disease, medications can usually cure it.

Reviewed 4/1/2022

Related stories