Seasonal allergies and colds share common symptoms but have different causes, according to Sandra Hong, MD, in the department of Pulmonary, Allergy and Critical Care Medicine.
They are often confused, but she says you can tell them apart by noting:
1. How symptoms develop
Both allergies and colds cause sneezing, nasal congestion, runny nose, watery eyes, and fatigue. However, colds often cause symptoms one at a time: first sneezing, then a runny nose and nasal congestion. Allergies cause these symptoms all at once.
2. How long symptoms last
Cold symptoms generally last seven to 10 days while seasonal allergy symptoms generally last months at a time. Seasonal allergy symptoms continue as long as you are exposed to the allergen (symptom trigger). The symptoms will subside soon after exposure to the allergen ends.
3. The type of mucus discharge
Colds may cause a yellowish nasal discharge, suggesting an infection. Allergies generally cause a clear, thin, watery discharge.
4. How often you sneeze
Sneezing is more common with allergies (especially sneezing two to three times in a row).
5. The time of year
Colds are more common during the winter months, whereas seasonal allergies are more common in spring through fall, when trees, grass, and weeds pollinate. Indoor allergies affect people year-round.
6. The presence of fever
Colds may be accompanied by a fever. Allergies are not usually associated with a fever.
7. The presence of itching
Itching is typical of allergies and it may affect eyes, nose, throat, and ears. Colds do not typically cause itching of any sort.
If you think you might have allergies, if your cold symptoms seem severe or if you are not getting better, see your doctor.