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Symptoms - Malaria

Symptoms of malaria can develop as soon as 7 days after you're bitten by an infected mosquito.

The time between infection and when symptoms start is normally 7 to 18 days. This depends on the specific parasite you're infected with. In some cases it can take up to a year for symptoms to develop.

The initial symptoms of malaria are flu-like and include:

These symptoms are often mild. They can sometimes be difficult to identify as malaria.

With some types of malaria, the symptoms occur in 48-hour cycles. During these cycles, you feel cold at first with shivering. You then develop a high temperature, accompanied by severe sweating and fatigue. These symptoms usually last between 6 and 12 hours.

The Plasmodium falciparum parasite causes the most serious type of malaria. This type can lead to you developing severe complications without prompt treatment. These include breathing problems and organ failure.

Get immediate medical advice

You must seek medical help straight away if you become ill while travelling in an area where malaria is found, or after returning from travelling, even if you've been taking antimalarial tablets.

Malaria can get worse very quickly, so it's important that it's diagnosed and treated as soon as possible.

If you develop symptoms of malaria while still taking antimalarial tablets remember to tell your GP which type you have been taking. The same type of antimalarial should not be used to treat you as well.

If you develop symptoms after returning home, contact your GP. Tell them which countries you've travelled to in the last 12 months, and include any stopovers.

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 23 March 2021
Next review due: 23 March 2024

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.