Illness & Symptoms
How long does a fever last?
Estimated wait
~4 days
Based on published sources
Timeline guide
- Faster cases~4 days
- Average cases~4 days
- Slower casesUp to 7 days
A fever still present after 48–72 hours, climbing, or not improving with home care is the point to seek medical advice — that is a threshold, not the expected duration. In babies under 3 months, any fever warrants urgent care.
A fever from a common viral illness usually settles within a few days. The CDC notes that uncomplicated flu — fever being the acute part — typically resolves in 3 to 7 days, with the fever itself often breaking around day 3–4.
More details
A fever is a symptom, not an illness, so how long it lasts depends entirely on the underlying cause. It usually eases as that illness runs its course.
Last updated: 4 Jul 2026
Information is for general knowledge only.