What causes malaria?

The parasite enters the bloodstream during a mosquito bite and travels to the liver. It then returns to the blood, where it infects red blood cells and multiplies. Their breakdown can cause fever, chills, sweating, headache, tiredness, or muscle aches. Malaria is not caused by cold weather, ordinary food, or a virus, and normal social contact does not usually spread it. Rare transmission can occur through routes such as contaminated blood or from a pregnant person to a baby, which is why clinicians consider medical history as well as travel.

If fever develops after travel in a malaria-risk area, seek prompt medical assessment and give the clinician your itinerary and return date. A blood test is used to look for the parasite and may be repeated if symptoms persist. For prevention, use mosquito protection and ask about malaria prophylaxis before travel; a travel health consultation allows advice to account for destination, health conditions, and other medicines.

Seek emergency care if fever is accompanied by confusion, fainting, seizure, severe breathing problems, repeated vomiting, or rapidly increasing weakness. These symptoms can signal serious malaria and should not be managed by waiting at home. Mention any recent travel even if you do not remember a mosquito bite.

Ask whether your exposure requires immediate testing, whether another test may be needed, and which treatment is appropriate for the parasite involved. Ask how to protect yourself and others from further mosquito transmission while you recover.