Malaria affects the circulatory and immune systems of the body, according to Malaria.com. It does this by attacking the body's red blood cells and destroying them.
Once infected through a mosquito bite, a person can have the malaria parasite dormant in the liver for 1 to 4 weeks, sometimes longer. The parasite then leaves the liver, entering the blood stream and infecting red blood cells. As more and more red blood cells are destroyed by the malaria parasite, toxins begin to build up as the body's immune system becomes compromised.
People can experience fever, chills, diarrhea, headaches, nausea, vomiting and a general feeling of being unwell. Malaria can be cured, but if the malaria goes untreated, it can become very severe, leading to kidney failure, hemorrhages, serious liver complications, shock, coma and death.
There are multiple types of malaria, and they each affect the body in their own ways. One particular type, Plasmodium falciparum, actually modifies the surface of the red blood cells that it infects. This causes the infected red blood cells to become sticky and start to lodge into blood vessels, clogging them and eventually cutting off the circulatory supply of blood flow and oxygen to the major organs of the body. This means that numerous organs, not just the liver and kidneys, can be affected. This process is called sequestration and can cause serious organ damage. Sequestration can even affect the brain, causing cerebral malaria. When this happens the brain doesn't get enough blood flow and oxygen. People go into comas, have psychiatric problems and can even die.