Fever in Adults: When to Worry
Most fevers are benign — some are not.
Dr. Hélène Marquet
Internist
In simple terms
Fever is a defence mechanism, not a disease. Knowing when it warrants urgent care is essential.
What you need to remember
- Red flags — Stiff neck, confusion, photophobia (meningitis)
- Vulnerable groups — Older adults, immunosuppression, pregnancy, post-chemotherapy: lower thresholds for medical review.
- Self-care — Adequate hydration, paracetamol or ibuprofen for comfort, rest.
Body temperature at least 38°C orally. Variation through the day is normal; rectal readings run slightly higher.
Red flags
- Stiff neck, confusion, photophobia (meningitis)
- Severe headache
- Difficulty breathing
- Chest or abdominal pain
- Rash that does not blanch under pressure
- Fever > 5 days or > 40°C
- Recent return from a malaria-endemic area
Vulnerable groups
Older adults, immunosuppression, pregnancy, post-chemotherapy: lower thresholds for medical review.
Self-care
Adequate hydration, paracetamol or ibuprofen for comfort, rest. Tepid sponging is not generally recommended.
Treat the person, not the thermometer: fever itself is rarely the danger.
The words explained
Medical terms used above, in everyday language.
- Immune system
- Your body's defence team: cells that fight germs and repair damage.
When should you see a doctor?
- Your symptoms last more than a few weeks or keep coming back.
- They get worse quickly, or stop you doing everyday things.
- You notice sudden pain, breathing trouble, fainting or bleeding — seek urgent care.
- You already take medication and want to change anything about it.
This article explains general health information. It does not replace advice from your own doctor.
Frequently asked questions
- What is Fever in Adults: When to Worry?
- Fever is a defence mechanism, not a disease. Knowing when it warrants urgent care is essential.
- What are the main symptoms or signs of Fever in Adults: When to Worry?
- Common signs vary from person to person. The article above lists the symptoms to watch for, how they progress, and when they need medical attention.
- When should you see a doctor for Fever in Adults: When to Worry?
- See a doctor if symptoms last more than a few weeks, get worse quickly, stop you doing everyday things, or if you notice sudden pain, breathing trouble, fainting or bleeding.
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