Malaria, an infectious mosquito-borne disease, can have many symptoms, depending on the severity of the disease. Fever, joint pain, and flu-like symptoms are common, with sudden chills and shaking followed by a high fever being a characteristic symptom. In children, malaria can cause mild cognitive impairments to severe brain damage, though the reasons for this are poorly understood. Lastly, the disease sometimes causes retinal whitening, which is a symptom helpful in distinguishing a malaria fever from a fever caused by something else. There are five known species of the infection; some species are generally not fatal, while one type of malaria can sometimes kill a human within hours of being bitten by an infected mosquito.
A classic symptom of malaria infection is a fever following rigor and coldness in an attack that lasts up to 10 hours. Basically, the person first feels very cold and then acquires a high fever, usually accompanied by a headache. When the malaria infection is uncomplicated, a sweating stage follows, and a person's temperature returns to normal, leaving him or her feeling tired but otherwise fine and showing few or no symptoms. This attack typically occurs once a day every two or three days, depending on the type of malaria. Generally, the infected person will begin to experience the fever attacks one week to one month after being infected, though it is not uncommon for the attacks to begin much sooner or later.
In addition to fever, many flu-like symptoms typically accompany all species of malaria infection. These symptoms include gastrointestinal issues such as vomiting, diarrhea, and nausea. General and localized muscular pain, general mental feelings of sickness, and coughing are also common.
Plasmodium falciparum is almost always responsible for severe malaria, which is the cause of the vast majority of deaths by malaria infection. With severe malaria infection or complicated malaria, the person tends to feel miserable even between fever attacks. Without treatment, the person will usually experience organ failure, seizures, or other medical emergencies until he or she dies. It is possible to survive severe malaria without treatment, but the infected person may sustain brain damage, especially if the person a growing child.
A particularly rare complication of a malaria infection is chronic malaria. Typically happening after an individual has contracted certain species of malaria multiple times, it can relapse unexpectedly. Even if the bloodstream of an individual is clear of malaria, the parasites can hide in the liver before reinfecting. Some of the noted symptoms of this condition are emaciation, enlargement of the spleen, and depression.
