Causes of fever

Woman and baby with a fever

How does fever occur?

Fever occurs when the hypothalamus resets the normal temperature point to a higher level. Though the body is still working to balance the heat produced with that which it releases, since the set-point is now higher, the body temperature rises.1

The increase in body temperature occurs due to various reasons such as release of certain chemicals called cytokines in response to invading microorganisms, cancer cells or any other foreign matter. It is also in response to the body producing white blood cells and antibodies to protect it from the invading foreign matter.2

Common causes of fever

  • Baby smiling

    Infectious causes of fever3,4

    Any form of infection can cause the body to respond with a fever. These include viral and bacterial infections. Some examples are:

    Viral infections:

    • Common cold
    • Influenza
    • Meningitis
    • Dengue fever
    • Gastroenteritis

    Bacterial infections:

    • Dysentery
    • Bacterial pneumonia
    • Tuberculosis
    • Skin infections
    • Urinary tract infections
    • Otitis media (ear infections)
    • Eye infections

  • Woman with a fever

    Though it is more common for a person to develop fever because of an infection, there are non-infectious causes of fever. These include:

    Auto-immune diseases:

    • Systemic lupus erythematosus (SLE)
    • Rheumatoid arthritis

    Cancers:

    • Leukaemias
    • Lymphomas

    Drug induced:

    • Sulfa drugs
    • Some anti-epileptic medications
    • Antiretroviral medicines (for treatment of HIV)
    • Some antiarrhythmic medications (e.g. amiadarone)

    Crystal-induced arthropaties:

    • Gout (accumulation of uric acid in the joints)

    Thromboembolism:

    • Deep vein thrombosis

    Abdominal conditions:

    • Acute pancreatitis

    Central nervous system conditions:

    • Stroke (haemorrhagic and ischaemic)

  • Baby smiling

    Some of the more common causes of fever in children are:

    • Upper respiratory tract infections
    • Influenza
    • Ear infections
    • Roseola which is caused by a virus and associated with a rash
    • Tonsillitis
    • Common childhood illnesses e.g. chicken pox
    • After immunisations

    However, contrary to popular believe, teething does not cause fever. There may be a slight increase in temperature during teething due to the irritation of the gums, but it is not high enough to qualify as a fever.7 This is important to remember as, if the child who is teething has a fever, then there may be an underlying infection that should be treated.

Understanding fever

Signs and symptoms

Fever overview

Find out the basics about fever.

Overview

Signs and symptoms

How do they present?

Refresh your knowledge on the signs and symptoms of fever and learn about “red flag” symptoms that indicate a referral to the doctor.

Signs and symptoms

Medicines

What can you recommend to your patients for fever?

Find out more about both non-pharmacological and pharmacological treatments for fever in both adults and children.

Management

Learn more

Crocin 650 pack shot

Releases paracetamol 2X faster8*

With 2x faster disintegration and absorption than standard paracetamol tablets, Crocin 650 relieves pain faster8 and can be taken even on an empty stomach.9,10†

Find out more

Pharmacist smiling

Learning module for pharmacists

A useful tool specifically tailored for pharmacists to treat children’s fever and pain using appropriate over-the-counter products.

Get it now

Crocin 240 packshot

Tough** on fever and pain,11 gentle on the child11,12‡

Crocin for children contains paracetamol which is recommended as first-line treatment for fever and mild-to-moderate pain in children.12-14 It starts to relieve fever within 15 minutes.11,15,16†

Learn more