Get emergency help now if…
- Get emergency help for confusion, severe breathing trouble, difficulty waking, or fever with severe headache, stiff neck or a rash that does not fade when pressed. Do not wait for a rash.
- Get emergency care for fever or a recent fever with severe belly pain, persistent vomiting, bleeding, black stool, or cold clammy skin—especially if dengue is possible. Warning signs can start as fever falls.
Contact a clinician today if…
- Fever during/recent chemotherapy or with known low white blood cells: contact your cancer team immediately. If unavailable, get urgent medical assessment now. Ask the team before taking fever medicines, which can mask infection.
- Contact a clinician today if fever worsens or does not improve, you cannot keep fluids down, or you have weakened immunity.
Arrange a visit / follow-up
- Arrange follow-up for repeated mild fevers after the urgent illness has been assessed.
If symptoms worsen, your care plan gives an earlier deadline, or you are unsure, contact a clinician sooner. If you cannot reach your team, use urgent care; use emergency care for severe symptoms. Many conditions share symptoms. Possible causes are examples, not a diagnosis. Missing a listed warning sign does not mean it is safe to wait.
What could be behind this symptom?
Several conditions can cause the same symptom. These examples cannot confirm or rule out a diagnosis. A clinician may need your history, an examination, or tests.
Possible causes include viral or bacterial infection and other inflammatory conditions. Temperature alone cannot show severity.
What to tell your care team
Use paper or your own notebook. Do not send personal medical details through this website.
- Record temperature, start date, medicines, travel and other symptoms.
Do not delay urgent care to fill in notes. Avoid changing prescription medicines based on this guide.
Adults, with extra care for some situations
For adults 18 and older. Children need advice from a pediatric care team. These pages do not assess your individual symptoms.
These guides are written for adults. Children need age-specific advice. Contact a clinician earlier if you are pregnant, gave birth in the last year, have weakened immunity, or have a serious ongoing condition. Tell them about recent surgery and any new medicines.
Pregnant or gave birth within the past year? Get medical care immediately for a severe or lasting headache, vision change, fainting, fever, chest pain, trouble breathing, severe belly pain, heavy bleeding, or a painful swollen leg. Tell the team about the pregnancy. For other new symptoms, contact your maternity team for tailored advice.
Pregnant or gave birth in the past year?Sources behind this original guide
Official references support this educational guide. Sources may open an external site in another language; the full English, Spanish, and Hindi guide is on this website.
- NHS: Fever in adults
- MedlinePlus: Fever
- NHS: Meningitis
- NHS: Sepsis
- India NCVBDC: Dengue warning signs (2023 clinical guidance)
- NCI: Infection and neutropenia during cancer treatment
Sources checked: · Medical and language review confirmed by the foundation · v1.0