Early diagnosis of malaria is critical for a patient's recovery. Any individual showing signs of malaria should be tested immediately. The WHO strongly advise parasitological confirmation by microscopy or a rapid diagnostic test (RDT).

The choice of testing method is, of course, dependent on the medical facilities available. RDT has become popular worldwide due to its capacity to provide a quick diagnosis.

RDTs are increasingly used as health care professionals seek to not only improve testing methodologies, but also to ensure that the opportunity for testing reaches a wider audience. The number of RDTs distributed by national malaria control programs around the world has increased substantially. In 2005, less than 200,000 RDTs were provided, in 2012 this number had risen to 108 million.

The signs and symptoms of the disease are non-specific. However, malaria is clinically suspected on the basis of fever, or a history of fever. Unfortunately, there is no combination of symptoms that can reliably distinguish the disease from other causes, hence the importance of a parasitological test.

In some malaria-endemic areas, such as sub-Saharan Africa, the disease is so intense that a large proportion of the local population can develop a mild immunity to the disease. As a result, some people can still carry the parasites in their bloodstream, but do not fall ill.