The symptoms of Legionnaires’ disease can begin any time from two to 19 days after exposure to the initial infection. However, six to seven days is the most common time between getting the infection and the onset of symptoms (incubation period).
Symptoms usually begin with an initial phase that lasts one to two days, in which you experience:
- mild headaches
- muscle pain
This is followed by the onset of more severe symptoms, including:
- high fever, sometimes a temperature of 38ºC (100.4ºF) or above
- more severe muscle pain
- chills
- tiredness
- changes to your mental state, such as confusion
Once the bacteria begin to infect your lungs, you may also experience:
- a persistent cough, which is usually dry at first but as the infection develops you may start coughing up mucus or, rarely, blood
- shortness of breath
- chest pains
Some people with Legionnaires’ disease also have symptoms that affect the digestive system, including:
- feeling sick
- being sick
- diarrhoea
- loss of appetite
When to seek medical advice
The symptom of a high fever is almost always caused by an infection. If you have a high fever, contact your GP as soon as possible to consider the various possibilities. Alternatively, you can telephone NHS Direct on 0845 4647 for advice.
