Symptoms of outdoor allergies usually start immediately after exposure to an airborne allergen. Symptoms may include:

• itchy, watery eyes
• red eyes (conjunctivitis)
• sneezing
• coughing
• runny nose (rhinitis)
• nasal congestion
• an itchy feeling in the nose, roof of the mouth, or throat
• sinus pressure and facial pain
• decreased sense of smell or taste
• sore throat (especially after waking, due to post-nasal drip and mouth-breathing)
• asthma symptoms: shortness of breath, coughing and wheezing

For some people, outdoor allergies interfere with daily life by causing difficulty sleeping, fatigue, and irritability.

Symptoms often start at a similar time each year due to the presence of pollen from particular plants to which you are allergic. For most people, symptoms of outdoor allergies tend to diminish with age, but the process is very slow, often taking decades to completely resolve.

Outdoor allergy symptoms may mimic a cold, but there are important differences between colds and allergies. Colds are usually accompanied by a low-grade fever and thick yellow or greenish discharge from the nose, while allergies are not. Colds also take a few days to develop after exposure to a cold virus and last up to a week, while allergy symptoms begin immediately upon exposure to an allergen and last as long as exposure to the allergen does.