Persistent Low-Grade Fever After Viral Infection: What to Know

Since a certain day when I caught a chill, I have been experiencing a persistent low-grade fever?

Since last Tuesday, there has been continuous wind, and starting from Wednesday, I experienced mild throat pain along with a body temperature ranging between 37°C and 37.8°C.
The next day, I had diarrhea for a day, but it resolved the following day.
Since then, I have had a lack of appetite and bloating.
I went to a large hospital for blood tests, and both my white blood cell count and inflammatory markers were normal.
However, it has now been over a week, and I still have a low-grade fever ranging from 37°C to 37.7°C, along with a persistent lack of appetite.
In the mornings and evenings, my temperature is between 36.5°C and 37°C, while in the afternoons, it is typically between 37.1°C and 37.5°C.
Additionally, my body temperature tends to rise whenever I eat, fluctuating between chills and heat.
Both the small clinic and the large hospital have diagnosed me with viral gastroenteritis, but I have never experienced a low-grade fever lasting this long, and I am unsure about the underlying cause.

Miss Lin, 20~29 year old female. Ask Date: 2023/03/09

Dr. Liao Yaopan reply Family Medicine

Hello, there are many possible reasons for an elevated body temperature, with the most common being infections.
Other potential causes include inflammatory diseases or tumors.
If the high temperature persists, it is advisable to have an evaluation by an infectious disease specialist.
Online consultations do not equate to in-person medical visits and cannot provide a diagnosis or treatment recommendations.
Changhua Hospital cares about your health.

Reply Date: 2023/03/09

More Info

Persistent low-grade fever can be a perplexing and concerning symptom, especially following a viral infection. In your case, it appears that you have been experiencing a low-grade fever ranging from 37°C to 37.8°C for over a week, accompanied by gastrointestinal symptoms such as loss of appetite and bloating. Given that you have already undergone blood tests that returned normal white blood cell counts and inflammatory markers, it is essential to consider several factors that could contribute to your ongoing symptoms.

Firstly, low-grade fevers can be a common response of the immune system to infections, including viral infections. After an initial viral illness, it is not unusual for the body to continue to exhibit mild fever as it works to clear the virus and recover. This phenomenon is sometimes referred to as post-viral fatigue or post-viral syndrome, where the body takes time to return to its baseline state after an infection.

Additionally, your symptoms of fluctuating temperature, chills, and heat sensations could indicate that your body is still in the process of regulating itself after the viral infection. The gastrointestinal symptoms you mentioned, such as diarrhea and bloating, could also be part of a post-viral syndrome, particularly if you experienced viral gastroenteritis. This condition can lead to prolonged recovery times, especially if your gut flora has been disrupted.

It is also worth noting that stress and fatigue can exacerbate symptoms and prolong recovery. If you have been under significant stress or have not been able to rest adequately, this could contribute to your persistent low-grade fever and gastrointestinal discomfort. Stress can impact the immune system, making it less effective in combating residual viral effects.

In terms of management, it is crucial to focus on supportive care. Ensure you are staying well-hydrated, eating a balanced diet, and getting plenty of rest. If your appetite is low, consider small, frequent meals that are easy to digest. Foods rich in probiotics, such as yogurt or fermented foods, may help restore gut health after a viral infection.

If your symptoms persist beyond a few more days or worsen, it would be advisable to follow up with your healthcare provider. They may consider further investigations, such as imaging studies or additional blood tests, to rule out other potential causes of your symptoms, including other infections or underlying conditions that may not have been apparent in initial evaluations.

In summary, while persistent low-grade fever following a viral infection can be concerning, it is often a part of the recovery process. However, continued monitoring of your symptoms and maintaining open communication with your healthcare provider is essential to ensure that any underlying issues are addressed promptly. If you experience any new or worsening symptoms, such as significant abdominal pain, persistent vomiting, or changes in consciousness, seek medical attention immediately.

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