What should you know about untreated malaria?

Malaria is an infection spread by infected mosquitoes. It may begin with fever, chills, sweating, headache, or muscle aches, but symptoms can change and may come in episodes. Without treatment, the infection can cause worsening weakness, confusion, breathing problems, seizures, severe anaemia, or problems involving the kidneys and other organs. A fever after travel or residence in a malaria area should be treated as a medical concern, even if you feel better between episodes.

Seek urgent medical assessment and tell the clinician where you have travelled, when you returned, and whether you used malaria prevention. Diagnosis may involve a blood test, sometimes repeated because parasites may not be detected early. Do not rely on leftover medicines or wait for the fever to settle. Drink fluids if you can, rest, and use only medicines recommended for you. Keep a record of fever, chills, vomiting, confusion, or reduced urine to share with the clinician.

Go to an emergency service immediately for confusion, fainting, a seizure, trouble breathing, repeated vomiting, inability to drink, severe weakness, yellowing of the eyes, or very little urine. A child, pregnant person, older adult, or person with reduced immunity should be assessed urgently after possible exposure. Do not wait for all symptoms to appear: malaria can deteriorate between bouts of fever.

Ask which tests are needed and whether they must be repeated; which malaria species or travel exposures are being considered; how treatment should be taken; what warning signs require emergency care; and how to prevent malaria during future travel.