Malaria is caused by the bite from an infected mosquito. The mosquito passes parasites into the blood that infect and destroy blood cells.

Rarely, malaria is spread by a transfusion of blood that contains parasites.

Malaria Cycle
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Risk Factors

The risk of malaria is highest in people who live in or travel to tropical climates. Malaria is most common in Africa, Asia, and Latin America.



Symptoms appear 10 days to 4 weeks after a mosquito bite. Problems may be:

  • Fever and chills
  • Nausea or vomiting
  • Headaches
  • Cough
  • Muscles aches
  • Loss of hunger
  • Diarrhea
  • Yellow coloring of the eyes and skin
  • Dark urine (pee)


The doctor will ask about symptoms and past health. Questions will also be asked about recent travel. A physical exam will be done. Malaria is diagnosed with blood tests.



Medicine will be given to kill the parasite. The type of medicine depends on:

  • The type of parasite
  • The stage of infection
  • Medicines that were taken to prevent malaria
  • Other health conditions, such as pregnancy


When traveling to areas where malaria is common, risk may be lowered by:

  • Taking medicine to prevent it
  • Avoiding mosquito bites by:
    • Covering up the skin
    • Using bug sprays, netting, and screens

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.