Overview
Malaria is an infectious disease caused by Plasmodium parasites. People usually get it after being bitten by an infected Anopheles mosquito. The illness ranges from mild to severe, and some forms can quickly affect the brain, lungs, kidneys, or blood. Early recognition and treatment are important.
Key Symptoms
Symptoms often include fever, chills, sweating, headache, tiredness, muscle aches, nausea, and vomiting. Some people also have diarrhea, cough, or abdominal pain. Symptoms can start days to weeks after a mosquito bite, and in some forms they may appear later. Severe malaria may cause confusion, trouble breathing, seizures, extreme weakness, or yellowing of the eyes or skin.
Causes and Risk Factors
Malaria is caused by several types of Plasmodium parasites, with Plasmodium falciparum often linked to the most severe illness. The main risk factor is being in an area where malaria is present and being bitten by infected mosquitoes, especially from dusk to dawn. Risk is also higher if a person does not use mosquito protection or preventive medicines when recommended. Rarely, malaria can spread through blood transfusion, shared needles, or from a pregnant parent to a baby.
Who Is Affected
Anyone exposed to infected mosquitoes in malaria-endemic areas can get malaria. Young children, pregnant people, travelers from places without malaria, older adults, and people with weakened immune systems may be at higher risk of severe disease. People living in or visiting parts of sub-Saharan Africa, Asia, Latin America, Oceania, and some other tropical and subtropical regions may be affected.
Prevention
Prevention focuses on avoiding mosquito bites and following travel health advice. Measures include sleeping under insecticide-treated bed nets, using insect repellents, wearing long sleeves and pants, and staying in screened or air-conditioned rooms when possible. Travelers to malaria-risk areas may need preventive antimalarial medicine based on the destination and their health needs. In some countries, malaria vaccines are being used for certain children as part of public health programs.
Diagnosis and Tests
Malaria cannot be confirmed by symptoms alone because it can look like many other illnesses. Healthcare professionals usually diagnose it with a blood test that looks for the parasite or its markers. Repeat testing may be needed if malaria is strongly suspected but the first test is negative. Quick testing matters because severe malaria can worsen fast.
Treatment Categories
Malaria is treated with prescription antimalarial medicines chosen based on the parasite type, where the infection was acquired, illness severity, pregnancy status, and local resistance patterns. Severe malaria usually requires urgent hospital treatment. It is important to complete treatment exactly as directed by a qualified clinician. Follow-up may be needed to confirm that the infection has cleared.
When to Seek Medical Care
Seek medical care promptly for fever, chills, or flu-like symptoms during travel in a malaria area or after returning home. Tell the clinician where you traveled and when. Do not wait for symptoms to become severe, because malaria can progress quickly. Babies, young children, pregnant people, and anyone with a weakened immune system should be assessed without delay.
When It May Be an Emergency
Get urgent medical help right away for confusion, seizures, fainting, trouble breathing, severe weakness, signs of dehydration, inability to drink, repeated vomiting, or a person who is hard to wake. Emergency care is also needed for symptoms of shock, very high fever with severe illness, or any rapidly worsening condition after possible malaria exposure. Severe malaria can be life-threatening within a short time.