SymptomLast reviewed: 07 Feb 2026

Fever in Adults: What to Watch, What Tests Help

A practical fever guide covering emergency signs, common causes, suggested tests, and when to see a doctor.

Key Takeaways

  • Most short fevers are self-limited but need monitoring.
  • Red-flag symptoms always require urgent in-person care.
  • Lab tests are chosen based on clinical suspicion, not by default.

Red Flags: Seek Urgent Care

  • Urgent care is needed for breathing difficulty, confusion, persistent vomiting, severe dehydration, seizures, chest pain, or very low urine output.

Quick Answer#

Fever is usually a response to infection and often improves with rest, hydration, and symptom care. Persistent or high fever needs evaluation.

Emergency Signs#

Urgent care is needed for breathing difficulty, confusion, persistent vomiting, severe dehydration, seizures, chest pain, or very low urine output.

Common Causes#

Viral infections, bacterial infections, urinary infections, respiratory infections, and inflammatory illnesses can cause fever.

Suggested Tests#

Doctors may suggest CBC, CRP, urine routine, dengue tests, malaria tests, chest imaging, or targeted culture based on symptoms.

What To Do Now#

Hydrate well, monitor temperature, use doctor-advised fever medicine, and track associated symptoms.

When To See A Doctor#

See a doctor if fever lasts more than 2 to 3 days, crosses high ranges repeatedly, or appears in elderly, pregnant, or high-risk patients.

Frequently Asked Questions

How many days of fever is concerning?

If fever lasts beyond 2 to 3 days or worsens, medical review is recommended.

Should everyone get a dengue test immediately?

Testing depends on symptoms, timing, and local epidemiology. A doctor decides the right panel.

Editorial & Medical Review

Author

PingMeDoc Editorial Team

Clinical Content Desk

Medical Reviewer

Dr Balaji Krishnan

MBBS, MBA

Medical Reviewer

Last Reviewed

07 Feb 2026

Content updates follow editorial and clinical review workflow.

References

  1. 1. WHO: Dengue and severe dengue - WHO (2025) Source

Related Reading

Curated links

Next Steps

Book a Relevant Test

Start with a lab test that helps clinical evaluation.

Consult a Doctor

Discuss symptoms and report findings with a clinician.

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