4 doctors weighed in:
How do I know if I have virus or allergy?
4 doctors weighed in

Dr. Pedro Hernandez
Internal Medicine - Geriatrics
3 doctors agree
In brief: Fever?
Viruses affect the whole body with muscle pains, sore throat, cough, increase phlegm/sputum production, fever.
Allergies cause itchiness, watery and burning eyes, sneezing but less likely muscle pains cough or fever. Both cause nasal discharge ( clear if allergic, green or yellowish with viruses or bacteria) and nasal congestion with obstruction, possible itchy throat.

In brief: Fever?
Viruses affect the whole body with muscle pains, sore throat, cough, increase phlegm/sputum production, fever.
Allergies cause itchiness, watery and burning eyes, sneezing but less likely muscle pains cough or fever. Both cause nasal discharge ( clear if allergic, green or yellowish with viruses or bacteria) and nasal congestion with obstruction, possible itchy throat.
Dr. Pedro Hernandez
Dr. Pedro Hernandez
Thank
Dr. Edward Neilsen
Family Medicine
1 doctor agrees
In brief: Difficult
It is often difficult to tell which of these is bothering you, as they can both caues similar symptoms (runny nose, congestion, sore throat, fatigue, sinus pressure, etc).
Clinicians can sometimes tell them apart with blood work or appearance of the nasal mucosa (skin inside the nose), but often it doesn't matter because they are usually treated the same. Allergies, however, do not cause fevers.

In brief: Difficult
It is often difficult to tell which of these is bothering you, as they can both caues similar symptoms (runny nose, congestion, sore throat, fatigue, sinus pressure, etc).
Clinicians can sometimes tell them apart with blood work or appearance of the nasal mucosa (skin inside the nose), but often it doesn't matter because they are usually treated the same. Allergies, however, do not cause fevers.
Dr. Edward Neilsen
Dr. Edward Neilsen
Thank
Get help from a real doctor now
Dr. William Forsythe
Board Certified,
23 years in practice
171K people helped
Continue
108,000 doctors available
Read more answers from doctors