Causes of Hay Fever
The underlying causes of hay fever stem from an overactive immune response to normally harmless environmental substances. These substances, known as allergens, trigger the body’s immune system to release inflammatory mediators—primarily histamine—that cause the characteristic symptoms. Understanding the causes of hay fever is crucial for identifying triggers, selecting appropriate treatments, and implementing effective prevention strategies.
The most common allergens that cause hay fever include pollen, dust mites, pet dander, mould spores, and cockroach debris. Seasonal hay fever is predominantly caused by pollen from grasses, trees, and weeds. Tree pollen tends to be most problematic in early spring, grass pollen in late spring and summer, and weed pollen in late summer to early autumn. Individuals may react to one or multiple pollen types, depending on their geographic location and genetic predisposition.
Perennial hay fever happens all year and usually starts because of indoor allergens. Dust mites grow well in bedding, soft furniture, and carpets. Mould often appears in damp places like bathrooms and kitchens. Pet dander—tiny skin flakes from cats, dogs, and other animals—can stay in our homes long after the pets are gone. These allergens can lead to chronic nasal inflammation and other respiratory symptoms.
Causes of Hay Fever
Genetics play a significant role in the development of hay fever. Individuals with a family history of allergies, asthma, or eczema are at higher risk of developing allergic rhinitis. This inherited predisposition to allergic conditions is referred to as atopy. Environmental factors during early life, such as exposure to tobacco smoke, air pollution, and microbial diversity, may also influence the development of allergic sensitivities.
People who live in cities and follow modern lifestyles often have higher rates of hay fever. This may happen because they breathe in more air pollution and spend less time in natural environments. The “hygiene hypothesis” suggests that reduced microbial exposure in early childhood may impair immune system development and increase susceptibility to allergic diseases. Researchers are still studying this theory to see if it helps explain why allergic disorders are increasing around the world.
Climate change has also impacted the causes of hay fever. Rising temperatures and increased carbon dioxide levels could possibly contribute to longer pollen seasons and higher pollen production. This intensification of airborne allergens contributes to earlier onset and more prolonged hay fever symptoms for affected individuals.
Causes of Hay Fever
In some cases, occupational exposure can cause or worsen hay fever. People who work in farming, floristry, veterinary care, cleaning, or baking often come into contact with high levels of certain allergens. As a result, their risk of developing symptoms may be higher. Continued exposure without protective measures can lead to sensitisation and persistent allergic symptoms.
Understanding the causes of hay fever empowers individuals and healthcare providers to take preventive action. Identifying specific triggers through allergy testing, environmental assessment, and symptom tracking is essential for creating an effective management plan tailored to each individual’s needs.
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