Fever
Everything you need to know about Fever - symptoms, causes, treatment options available in Australia, and when to see a doctor. Evidence-based medical information.
Overview
Fever, a common clinical symptom, is characterised by an elevation in body temperature above the normal range, typically due to an underlying infection or inflammatory process.
How it works in your body (pathophysiology):
Fever affects your body through specific biological processes:
- Temperature rise: Fever means your body temperature goes above normal. This usually happens because of an infection or inflammation (swelling and redness).
- Role of the hypothalamus: The hypothalamus is a part of your brain that controls body temperature. During a fever, it changes the set point (desired temperature level) to make your body warmer.
- Purpose of fever: Fever helps your body fight off infections by making it harder for germs to survive. Understanding how fever works is important for treating it effectively.
Statistics and Prevalence in Australia
In 2024, the prevalence of fever in the Australian community was closely monitored through national respiratory surveillance systems. The peak prevalence of new fever and cough symptoms was reported at 2.6% in late June, according to FluTracking data [1]. This prevalence is consistent with previous years, indicating a stable pattern of fever occurrence during the flu season. Among adults experiencing fever symptoms, approximately half reported taking three or more days off from their usual duties [1]. Notably, higher rates of severe illness and hospitalisation were observed in individuals aged 65 and older, particularly in Queensland, where 62% of severe cases were reported in this age group [1].
Symptoms and Clinical Presentation
Fever is often accompanied by a range of symptoms, which can vary depending on the underlying cause. Early signs of fever include chills, sweating, headache, muscle aches, and general malaise. As the fever progresses, symptoms may include dehydration, weakness, and confusion, particularly in older adults. Red flag symptoms that warrant immediate medical attention include persistent high fever, severe headache, neck stiffness, rash, difficulty breathing, and altered mental status [2].
The clinical presentation of fever can differ across populations. In children, fever may present with irritability, poor feeding, and lethargy. In contrast, older adults may exhibit atypical symptoms such as confusion or falls. It is essential to recognise these variations to ensure timely and appropriate medical intervention [2].
Causes and Risk Factors
Fever can result from a variety of causes, most commonly infections such as viral, bacterial, or fungal pathogens. Other causes include inflammatory conditions, malignancies, and autoimmune disorders. The pathophysiological mechanisms involve the release of pyrogens, which trigger the hypothalamus to elevate the body's temperature set point [3].
Risk factors for developing fever include exposure to infectious agents, compromised immune function, chronic medical conditions, and certain medications. In Australia, seasonal factors such as the flu season contribute to the prevalence of fever, with higher incidence rates observed during the winter months [3].
Diagnosis
The diagnosis of fever involves a comprehensive clinical assessment to identify the underlying cause. Australian guidelines recommend a thorough history and physical examination, focusing on identifying any serious infections or clinical focus of fever. Laboratory investigations, including complete blood count, blood cultures, and inflammatory markers, may be necessary to pinpoint the cause [4].
In certain cases, imaging studies such as chest X-rays or CT scans may be warranted to assess for complications or specific infections. For infants aged 28 days or younger, prompt assessment and investigation are crucial due to their increased vulnerability to serious infections [4].
Treatment Options in Australia
Treatment of fever in Australia is guided by clinical practice guidelines from organisations such as the Royal Australian College of General Practitioners (RACGP) and the National Health and Medical Research Council (NHMRC). The primary goal is to address the underlying cause while providing symptomatic relief.
First-line treatment includes the use of antipyretics such as paracetamol or ibuprofen to reduce fever and alleviate discomfort. It is important to use these medications judiciously, particularly in children, to avoid potential side effects [5]. Antibiotics may be prescribed if a bacterial infection is identified, while antiviral medications are considered for specific viral infections such as influenza.
Non-pharmacological strategies, including adequate hydration, rest, and maintaining a comfortable environment, are also essential components of fever management. In severe cases or when complications arise, hospitalisation and more intensive interventions may be required [5].
Living with Fever
Managing fever effectively involves not only medical treatment but also patient education and self-care strategies. Patients are advised to monitor their symptoms closely, maintain hydration, and seek medical attention if symptoms worsen or do not improve with initial treatment [6].
For individuals with chronic health conditions or those at higher risk of complications, regular follow-up and monitoring are crucial to ensure optimal health outcomes. Patient education on recognising red flag symptoms and understanding when to seek medical care is vital for effective self-management [6].
Prevention
Preventing fever involves addressing the underlying causes and reducing exposure to infectious agents. Vaccination is a key preventive measure, particularly for influenza and other vaccine-preventable diseases. The Australian National Immunisation Program provides guidelines and recommendations for vaccinations across different age groups [7].
Good hygiene practices, such as regular handwashing, avoiding close contact with sick individuals, and maintaining a healthy lifestyle, can also reduce the risk of infections that may lead to fever. Public health initiatives and community awareness campaigns play a significant role in promoting preventive measures and reducing the prevalence of fever-related illnesses [7].