Q: I've had a 40°C fever for 5 days after a flu diagnosis, and my cough is worsening. Should I return to the hospital?
- Myeongchan Kim, MD
- Jul 9
- 2 min read
Updated: Jul 21
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:
The fever started a few days ago, peaking at 40°C. I went to the emergency room initially, but the flu test was negative as it had been less than 24 hours since the fever began. The next day, I returned to the ER, tested positive for the flu, received an antiviral injection, and came home with prescribed medication.
However, today is the 5th day since the flu diagnosis, and the fever still hasn't dropped, continuing to peak at 40°C. Furthermore, my cough seems to have worsened. Do I need to go back to the hospital for further testing?
Answer:
Experiencing a persistent high fever for 5 days along with a worsening cough after a flu diagnosis is certainly a concerning situation.
⚠️ A medical re-evaluation is highly necessary.
A continuous 40°C fever lasting 5 days after receiving flu treatment, combined with an aggravated cough, strongly suggests the possibility of complications:
【Please visit the hospital immediately】
• You need to be evaluated for secondary bacterial infections, such as pneumonia.
• A chest X-ray and blood tests may be necessary to assess your condition.
• The doctor may need to consider prescribing antibiotics.
【Go straight to the Emergency Room if you experience any of the following】
• Difficulty breathing or chest pain
• Blood mixed in your phlegm/sputum
• Confusion, sluggish reactions, or a blurry state of consciousness
• Inability to drink fluids, leading to signs of severe dehydration
Bacterial pneumonia is a relatively common complication that can follow the flu. A high fever lasting for 5 days is difficult to view as a normal progression of a simple flu virus, making a thorough re-evaluation absolutely essential.
Please visit the hospital for a check-up today. In the meantime, ensure you are drinking plenty of fluids to stay hydrated and continue taking your fever-reducing medications as needed.
For extra peace of mind and clear guidance when tracking your child's symptoms, the FeverCoach app is always there to help.
