Q: My child tested negative for the flu, but the fever continues. Should we get retested?
- Myeongchan Kim
- May 23
- 2 min read
Medically reviewed by Sang Hyun Ahn, MD
Content edited by Myeongchan Kim, MD
This post is a dramatization of a question and answer session experienced by our actual medical reviewers. Please note that this content is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional for any health concerns or before making any decisions related to your health or treatment.
Question:
A fever started around 7 PM yesterday at 38.3°C, and I alternated fever reducers until this morning. We went to the clinic this morning for a flu test, but the result was negative. Should we go back tomorrow and get retested? The fever peaks at around 38.3°C to 38.4°C and keeps going up and down. An acquaintance told me that the flu always starts with a very high fever. Is it best to get tested again?
Answer:
I completely understand your concern, especially when a fever persists despite a negative flu test.
Whether you should get retested depends on several factors. Here are situations where a retest is generally recommended:
Early testing: If the initial test was done within the first 12 to 24 hours of symptom onset, a retest after 48 hours may be considered.
High exposure risk: If it is currently flu season and there has been contact with a known flu patient, or if there is a confirmed flu case in your family.
Accompanying symptoms: If the fever is accompanied by sudden, severe body aches and headaches.
Regarding the fever, 38.3°C to 38.4°C is actually a very common temperature range for the flu. It is a misconception that the flu only begins with a high fever (39°C or above). The sudden onset of the fever and the presence of systemic symptoms are much more important indicators than the temperature alone.
Here are my recommendations for your current situation:
Monitor and Retest if Needed: Consider getting retested tomorrow if the symptoms worsen or if new symptoms (such as a cough or severe body aches) develop.
Supportive Care: For now, prioritize adequate rest and ensure plenty of fluid intake.
Fever Management: Give fever reducers only when the patient is uncomfortable, and be sure to maintain appropriate dosing intervals (e.g., every 6 hours depending on the medication).
Seek immediate medical attention if you notice warning signs such as shortness of breath, chest pain, persistent vomiting, or a decrease in consciousness (lethargy).
Because rapid flu tests can sometimes yield false-negative results, clinical symptoms are the most important factor to watch. Please follow up with your doctor or pediatrician to discuss the progression of the symptoms and determine if a retest is clinically necessary.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
