Malaria is caused by the Plasmodium parasite. The parasite can be spread to humans through the bites of infected mosquitoes.
There are many different types of plasmodium parasite, but only 5 types cause malaria in humans.
The plasmodium parasite is spread by female Anopheles mosquitoes, which are known as "night-biting" mosquitoes because they most commonly bite between dusk and dawn.
If a mosquito bites a person already infected with malaria, it can also become infected and spread the parasite on to other people. However, malaria can't be spread directly from person to person.
Once you're bitten, the parasite enters the bloodstream and travels to the liver. The infection develops in the liver before re-entering the bloodstream and invading the red blood cells.
The parasites grow and multiply in the red blood cells. At regular intervals, the infected blood cells burst, releasing more parasites into the blood. Infected blood cells usually burst every 48-72 hours. Each time they burst, you'll have a bout of fever, chills and sweating.
Malaria can also be spread through blood transfusions and the sharing of needles, but this is very rare.