It is caused by a mosquito bite. The mosquito passes parasites into the blood. They infect and destroy blood cells.

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

Malaria Cycle
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Risk Factors

The risk is highest for those 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. Common ones may be:

  • Fever and chills
  • Nausea or vomiting
  • Headaches
  • Cough
  • Muscles aches
  • Loss of hunger
  • Diarrhea

Sometimes there is also:

  • Yellow coloring of the eyes and skin— jaundice
  • Dark or discolored urine


Your doctor will ask about your symptoms, and health and travel history. A physical exam will be done. Malaria is diagnosed with blood tests.



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

  • The type of parasite
  • 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.