← Library
Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.
Respiratory / ImmunologyMild

Hay fever

Hay fever, also known as allergic rhinitis, is an allergic reaction to outdoor or indoor allergens. It causes cold-like symptoms such as a runny nose, itchy eyes, and sneezing during specific times of the year or year-round.

Severity
Mild
System
Whole body
Progression
Self-limited
Treatable
Yes — usually with self-care or routine treatment
Common age
All ages
Duration
Acute (days–weeks)
Contagious
No
Emergency risk
High
Whole body
Affected area: Whole body

Overview

Hay fever, also known as allergic rhinitis, is an allergic reaction to outdoor or indoor allergens. It causes cold-like symptoms such as a runny nose, itchy eyes, and sneezing during specific times of the year or year-round.

Understand this condition

When you have hay fever, your immune system mistakenly identifies harmless proteins like pollen as dangerous invaders. It produces antibodies to fight these substances, leading to the release of chemicals like histamine. These chemicals cause inflammation in the lining of your nose, throat, and eyes.

Why it happens

The biological reason is a hypersensitive immune reaction to environmental triggers. Symptoms typically progress shortly after exposure and can worsen if the inflammation becomes chronic. Over time, repeated exposure can make the airways more sensitive to even minor irritants.

Real-world scenarios

  • People may notice sneezing fits every time they mow the lawn.
  • This often appears as itchy, watery eyes during peak spring months.
  • People may experience a stuffy nose only when visiting homes with cats.
  • This often appears as a persistent nighttime cough during high mold seasons.

Common vs serious explanations

Common
  • Seasonal changes in plant pollination cycles
  • Exposure to a new pet or dusty environment
  • High wind carrying pollen from distant areas
  • Spending more time outdoors during peak seasons
Serious
  • Anaphylaxis, a life-threatening allergic reaction requiring immediate care
  • Severe asthma exacerbation causing significant airway narrowing
  • Acute bacterial sinusitis requiring antibiotic treatment
  • Nasal polyps blocking the airways and requiring surgery

Symptoms

Click any symptom to analyze
Primary symptoms

No symptoms mapped yet.

Causes

  • pollen from trees, grass, or weeds
  • dust mites
  • mold spores
  • pet dander / skin flakes

Risk factors

  • having other allergies or asthma
  • family history of hay fever or eczema
  • living or working in an environment with high allergen exposure
  • allergic sensitization in early childhood

How it progresses

3 stages
  1. Onset
    Symptoms appear, often triggered by a known cause.
    Often missed
  2. Active phase
    Symptoms peak; self-care or short treatment usually helps.
  3. Resolution
    Symptoms ease over days to weeks with proper care.

How it's diagnosed

  • physical examination of nasal passages
  • review of seasonal symptom history
  • allergy skin prick test
  • blood test for specific IgE antibodies

Treatment options

General educational information only — no dosage advice. Always follow guidance from a qualified clinician.

Medical
  • over-the-counter antihistamines
  • corticosteroid nasal sprays
  • decongestant medications
  • allergy immunotherapy (shots or tablets)
Home care
  • using a saline nasal rinse or neti pot
  • keeping windows closed during peak pollen times
  • showering after being outdoors
  • wearing sunglasses to protect eyes

Complications

  • Reduced quality of life
  • Worsening symptoms over time
  • Recurrence of hay fever

Prevention

  • Maintain a healthy lifestyle
  • See a clinician for routine check-ups

When to seek help

Urgent — same-day care
  • Symptoms persist beyond a few days
  • Symptoms interfere with daily activities
  • New or worsening symptoms appear
  • Concerning changes related to hay fever
🚨 Emergency — call now
  • wheezing or difficulty breathing
  • symptoms that do not respond to medication
  • severe facial pain and sinus pressure
  • fever or signs of secondary infection

In any emergency, call your local emergency number or go to the nearest emergency department.

Real-world questions

  • Can Hay fever cause headaches?
  • Is Hay fever reversible?
  • How quickly does Hay fever progress?
  • Is Hay fever hereditary?
  • Can Hay fever be prevented?

Frequently asked questions

What causes Hay fever?

Possible causes of Hay fever include pollen from trees, grass, or weeds, dust mites, mold spores, pet dander / skin flakes.

Is Hay fever dangerous?

Hay fever is generally mild, but severity can vary. Seek care if symptoms are severe or persistent.

How long does Hay fever last?

Duration varies between individuals. Many cases improve with appropriate care, while others may persist longer and require ongoing management.

Can Hay fever go away on its own?

Some milder cases may improve with rest and self-care. If symptoms persist or worsen, consult a healthcare professional.

When should I see a doctor about Hay fever?

Consider seeing a clinician if symptoms are severe, persistent, worsening, or if you have any concerns related to general.

Sources

Information based on general medical references such as:

CDCNHSWHOMedlinePlus

Last reviewed: May 2026

Try the symptom analyzer
Educational use only: Symptom.Today is an educational tool and does not provide medical advice, diagnosis, or treatment. Results are not a substitute for professional medical care. If symptoms are severe, worsening, or concerning, seek medical attention immediately. In an emergency, call your local emergency number.