What Is Malaria? Symptoms, Causes & Treatment Options | Skymeds
Updated: Sep 17
Written by Dr. Zack Ferris in TheSkyMeds Editorial Standards
Medically reviewed by Jonathan Reed, Medical Content Reviewer Jan 27 2026
Malaria is a potentially life-threatening infection caused by Plasmodium parasites and most commonly spread through the bite of an infected female Anopheles mosquito. Understanding what is malaria matters because early symptoms such as fever, chills and headache can resemble many other illnesses, while untreated infection—particularly Plasmodium falciparum malaria—can become severe quickly. WHO estimated 282 million malaria cases and 610,000 deaths worldwide in 2024. Malaria is both preventable and curable when it is recognized and treated appropriately. Diagnosis usually requires a blood test rather than symptoms alone. This guide from Skymeds explains malaria causes, symptoms, diagnosis, treatment options, warning signs and practical prevention measures.
What Is Malaria and What Causes It?
Malaria is an infectious disease caused by parasites of the genus Plasmodium. People usually become infected when a female Anopheles mosquito carrying the parasite bites them and introduces the parasite into the bloodstream.
Malaria is therefore not caused by a virus or bacterium. It is also not normally passed directly between people like a cold or influenza. Rare transmission routes can include contaminated blood or needles and transmission during pregnancy or birth.
Which parasites cause malaria?
Five Plasmodium species are recognized as causes of malaria in humans:
Plasmodium falciparum
Plasmodium vivax
Plasmodium malariae
Plasmodium ovale
Plasmodium knowlesi
Of these, P. falciparum and P. vivax present the greatest global threat. P. falciparum is the deadliest species and predominates in Africa, while P. vivax is dominant in many malaria-affected areas outside sub-Saharan Africa.
After an infected mosquito bites a person, parasites initially travel to the liver. They later enter red blood cells, where further multiplication produces the blood-stage infection responsible for malaria symptoms.
Malaria species | Practical significance |
P. falciparum | Can progress rapidly to severe or fatal disease |
P. vivax | Can form dormant liver stages and cause later relapses |
P. ovale | Can also remain dormant in the liver and relapse |
P. malariae | Occurs globally but is less common than the major species |
P. knowlesi | Zoonotic malaria found particularly in Southeast Asia; potentially severe |
Correct species identification matters because treatment and relapse prevention can differ.
What Are the Symptoms of Malaria?
The most common early malaria symptoms include fever, chills and headache. People may also experience tiredness, muscle aches, nausea, vomiting or diarrhoea, making malaria difficult to distinguish from other febrile illnesses based on symptoms alone.
WHO reports that symptoms commonly begin around 10–15 days after the bite of an infected mosquito, although timing varies. Some malaria species can persist in the liver and cause illness much later.
Common early symptoms
Possible symptoms include:
fever;
chills;
headache;
tiredness or weakness;
muscle aches;
nausea;
vomiting; and
diarrhoea.
A person does not need to experience every symptom. Malaria also cannot reliably be identified by a particular fever pattern at home.
ever after recent travel to or residence in a malaria-risk area deserves prompt medical assessment. Malaria symptoms are often nonspecific, and waiting for a “classic” pattern of fever and chills can delay diagnosis.
When does malaria become severe?
Severe malaria is a medical emergency. WHO lists warning features including extreme fatigue, impaired consciousness, repeated convulsions, difficulty breathing, dark or bloody urine, jaundice and abnormal bleeding.
Severe disease can also involve profound anaemia, kidney injury, circulatory problems and brain involvement. Untreated P. falciparum malaria can progress to severe disease and death within 24 hours.
Possible uncomplicated symptoms | Signs of potentially severe malaria |
Fever | Confusion or impaired consciousness |
Chills | Seizures |
Headache | Difficulty breathing |
Muscle aches | Severe weakness or extreme fatigue |
Nausea or vomiting | Dark or bloody urine |
Tiredness | Jaundice |
Diarrhoea | Abnormal bleeding |
General flu-like illness | Kidney failure, shock or coma |
Who Is Most at Risk of Severe Malaria?
Anyone infected with malaria can become seriously ill, but some groups have a higher risk of severe disease. These include young children, pregnant women, travellers without established immunity, and people living with HIV/AIDS.
Why does pregnancy require particular attention?
Malaria during pregnancy can threaten both mother and baby. WHO reports associations with premature delivery and low birth weight, while the choice of preventive and treatment medicines also needs to account for pregnancy.
Pregnant people should therefore obtain medical advice promptly if malaria is possible rather than choosing an antimalarial medicine independently.
Why are travellers vulnerable?
People living for long periods in malaria-endemic regions may develop some partial immunity following repeated exposure, although that protection is incomplete and can diminish.
Travellers from areas without malaria generally do not have this acquired protection. Anyone who develops fever after visiting a malaria-endemic area should tell their healthcare professional where and when they travelled—even if they took preventive medication.
How Is Malaria Diagnosed?
Malaria should be confirmed using a parasite-based diagnostic test rather than diagnosed from symptoms alone. WHO recommends testing suspected cases with microscopy or a malaria rapid diagnostic test before treatment whenever appropriate testing is available.
The WHO malaria fact sheet explains current recommendations for symptoms, testing, treatment and prevention.
Blood microscopy
Microscopic examination of blood can detect malaria parasites and help identify the Plasmodium species and parasite density.
Thick and thin blood smears remain important diagnostic tools. CDC guidance emphasizes that rapid and accurate identification helps clinicians choose appropriate treatment and assess the risk of severe disease.
Rapid diagnostic tests
Rapid diagnostic tests, or RDTs, detect malaria-related antigens in blood and can provide results relatively quickly. They are particularly valuable where high-quality microscopy is not immediately accessible.
Testing matters because fever, headache and chills have many possible causes. Treating every fever as malaria can delay the correct diagnosis of another illness.
How Is Malaria Treated?
Malaria is treated with prescription antimalarial medicines, but there is no single treatment regimen appropriate for every case. Treatment depends on the Plasmodium species, disease severity, local drug resistance, where the infection was acquired, age or weight, pregnancy status and other individual factors.
The current WHO guidelines for malaria provide detailed evidence-based recommendations for malaria prevention, diagnosis and treatment. WHO released its latest consolidated guideline update on September 10, 2026.
Treatment for uncomplicated malaria
Artemisinin-based combination therapies, commonly called ACTs, are central to treating uncomplicated P. falciparum malaria. These regimens combine an artemisinin derivative with another antimalarial medicine to improve parasite clearance and treatment effectiveness.
WHO-recommended ACT options include combinations such as artemether-lumefantrine and several other regimens. The appropriate regimen depends partly on national recommendations and local patterns of parasite resistance.
What about P. vivax and P. ovale malaria?
P. vivax and P. ovale require another consideration: dormant parasite forms can remain in the liver after the initial blood infection has been treated and later cause relapse.
Treatment may therefore include an additional medicine, such as primaquine, to eliminate these liver stages when medically appropriate. These medicines require clinical assessment because factors such as glucose-6-phosphate dehydrogenase (G6PD) status and pregnancy affect whether particular anti-relapse treatments can be used safely.
How is severe malaria treated?
Severe malaria requires urgent hospital treatment. Injectable artesunate is a key recommended treatment for severe malaria, followed by appropriate oral antimalarial therapy when the patient can tolerate it.
Treatment should not be delayed while someone tries home remedies or self-selected medicines.
Can Malaria Be Prevented?
Yes. Malaria risk can be reduced through a combination of preventing mosquito bites, controlling mosquitoes and, for people at appropriate risk, taking preventive antimalarial medicines.
Practical mosquito-bite precautions include sleeping under an insecticide-treated mosquito net where recommended, using effective mosquito repellent, wearing clothing that covers exposed skin, and using window screens or other barriers.
Preventive medicines for travellers
People travelling to malaria-risk destinations may need prescription medicines known as chemoprophylaxis. The correct drug depends on the destination, parasite resistance patterns, medical history and other factors.
Preventive medication does not replace mosquito-bite precautions, and no preventive medicine provides complete protection. Fever during or after travel therefore still needs medical attention when malaria exposure is possible.
WHO also recommends malaria vaccines for children in certain malaria-endemic settings as part of comprehensive malaria-control strategies. The WHO malaria guidance contains current recommendations covering vaccines and other preventive interventions.
When Should You Seek Urgent Medical Care?
Seek prompt medical assessment if you develop fever, chills, headache or flu-like illness after living in or travelling through an area where malaria occurs. Tell the healthcare professional about your travel history and any malaria-prevention medicines you took.
Emergency care is particularly important for confusion, loss of consciousness, seizures, breathing difficulty, severe weakness, jaundice, dark or bloody urine, abnormal bleeding, persistent inability to take fluids, or other rapidly worsening symptoms.
Do not try to determine the malaria species or choose treatment yourself based only on symptoms. P. falciparum can deteriorate particularly quickly, while correct treatment depends on diagnostic findings and individual circumstances.
Infants, young children, pregnant women and people with significant underlying illness warrant especially prompt assessment when malaria is suspected.
Conclusion
Knowing what is malaria can help you recognize why fever after possible mosquito exposure should not be ignored. Malaria is caused by Plasmodium parasites and usually spreads through infected Anopheles mosquitoes. Although fever, chills and headache are common, symptoms alone cannot confirm the diagnosis. Prompt testing and the correct antimalarial treatment can prevent uncomplicated infection from progressing to severe disease.
If malaria may be causing your symptoms, seek medical care rather than self-treating. Skymeds encourages informed medicine use alongside professional diagnosis and treatment, particularly for infections where the correct medicine depends on parasite species, resistance patterns and individual health factors.
Frequently Asked Questions
1 . Is malaria caused by a virus or bacteria?
Neither. Malaria is caused by Plasmodium parasites, which are usually transmitted through infected female Anopheles mosquitoes. Five parasite species can cause malaria in humans, with P. falciparum and P. vivax presenting the greatest global threat.
2 . What are the first symptoms of malaria?
Fever, chills and headache are common early symptoms. Tiredness, muscle aches, nausea, vomiting or diarrhoea may also occur. Because these symptoms resemble many other infections, suspected malaria should be confirmed through appropriate blood testing rather than symptoms alone.
3 . How long after a mosquito bite do malaria symptoms appear?
WHO says symptoms commonly begin about 10–15 days after an infected mosquito bite, although timing varies by parasite species and other factors. Some parasites can remain dormant in the liver and cause illness months or occasionally much later.
4 . Can malaria be completely cured?
Yes, malaria is generally curable when correctly diagnosed and treated promptly. Treatment depends on the parasite species, disease severity and drug-resistance patterns. P. vivax and P. ovale may also require treatment targeting dormant liver-stage parasites to help prevent relapse.
5 . Can malaria spread directly from one person to another?
Malaria does not normally spread between people through everyday contact. Most infections result from infected Anopheles mosquito bites. Less common transmission routes include contaminated blood or needles and mother-to-child transmission associated with pregnancy or birth.
6 . Is every fever in a malaria area malaria?
No. Many infections and other illnesses can cause fever, and malaria symptoms are often nonspecific. WHO recommends parasite-based testing for suspected malaria rather than assuming that fever alone confirms infection. Prompt testing helps patients receive the appropriate treatment.
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