Allergies happen when the immune system overreacts to normally harmless substances such as pollen, mold, or pet dander. Seasonal allergies cause sneezing, runny nose, and itchy eyes — not a true fever. First-line treatments include antihistamines and nasal corticosteroids; saline rinses and allergen avoidance are useful complements. Immunotherapy can reduce sensitivity long-term.
Allergies affect tens of millions of Americans and rank among the most common chronic health conditions in the country, according to the Asthma and Allergy Foundation of America (AAFA). When the immune system identifies a harmless substance — such as tree pollen or grass pollen — as a threat, it releases chemicals including histamine that produce the familiar symptoms: sneezing, congestion, and itchy, watery eyes. Understanding the full picture of pollen allergy, from symptoms to treatment options, helps you manage them more effectively throughout the year.
This guide covers seasonal allergies specifically — often called hay fever or allergic rhinitis — and walks through symptoms, how to treat them, what the research says about antihistamines and alternative remedies, and whether allergies can actually cause a fever (short answer: they cannot).
Seasonal allergies symptoms follow a recognizable pattern: they appear or intensify during specific times of year when particular plants release pollen. The ACAAI notes that the most common culprits are trees in spring, grasses in late spring and summer, and weeds — especially ragweed — in late summer and fall.
A key distinguishing feature: seasonal allergy symptoms do not include thick or colored discharge, body aches, or a temperature above 100.4 °F. If those signs are present, a respiratory infection is more likely. Symptoms that return predictably each year and improve after moving indoors or on rainy days (when pollen is lower) strongly point to allergies.
Hayfever and allergies are closely related terms, but they are not the same thing. "Allergies" is a broad category covering any immune overreaction — to foods, medications, insect stings, latex, or airborne particles. "Hay fever" (allergic rhinitis) is a specific subset: an allergic response to inhaled allergens such as pollen, mold spores, or animal dander, producing primarily nasal and eye symptoms.
The Mayo Clinic describes allergic rhinitis as one of the most common allergic conditions, affecting both children and adults. The misleading name "hay fever" dates back to early observations that symptoms worsened during hay-cutting season — but neither hay nor fever is actually involved. Pollen is the more accurate culprit, and symptoms occur without any rise in body temperature.
If you are unsure, an allergist can perform a skin-prick or blood test to confirm whether specific allergens are triggering your symptoms.
Allergic diseases have increased significantly in prevalence over recent decades, making allergies today a major public health concern. The AAFA reports that allergic rhinitis is one of the most common chronic conditions in the United States, affecting a substantial portion of the population — both adults and children.
Climate-related shifts in pollen seasons are contributing to a longer and more intense allergy season in many parts of the country. Warmer temperatures cause plants to begin pollinating earlier in spring and continue later into fall. The NIH/NIEHS has identified climate change as a factor in rising pollen concentrations and longer seasonal exposure windows, meaning that people who previously had mild or no symptoms may now notice them for the first time — or find that their existing symptoms have worsened.
People with asthma face particular challenges: allergic triggers are a leading cause of asthma flares, and managing seasonal allergies is often a core part of asthma care, per ACAAI guidelines.
Knowing how to treat seasonal allergies starts with understanding that no single approach works for everyone. Medical organizations including the Mayo Clinic and ACAAI recommend a layered strategy combining avoidance, medication, and — for eligible patients — immunotherapy.
Reducing exposure is the foundation of allergy management. Practical steps include:
Several drug classes are available without a prescription and are effective for most people with mild to moderate symptoms:
For people whose symptoms are not well controlled by OTC options, an allergist may recommend prescription medications or allergen immunotherapy. Immunotherapy — delivered as allergy shots or sublingual tablets — gradually desensitizes the immune system to specific allergens and can provide long-lasting relief, according to the ACAAI. It is the only treatment that addresses the underlying immune mechanism rather than just the symptoms.
Antihistamines for pollen allergies are among the most widely used medications in the US. They work by blocking histamine receptors, reducing sneezing, itching, and watery eyes that occur when the immune system encounters pollen.
There are two main generations:
Antihistamines are most effective for sneezing, itching, and runny nose. They are less effective at relieving nasal congestion; for that, a nasal corticosteroid or decongestant is a better choice. Taking antihistamines consistently during peak season — rather than only when symptoms appear — generally produces better results.
Common second-generation antihistamines. Always follow label instructions and consult a pharmacist or doctor if you have other health conditions or take other medications.
This is one of the most common questions allergists encounter: can allergies cause fever? The direct answer is no. Allergies trigger an immune response driven by IgE antibodies and histamine release — a different pathway from the one that produces a fever. A true fever (body temperature above 100.4 °F / 38 °C) is the body's response to infection or, less commonly, to inflammatory conditions unrelated to allergic rhinitis.
The confusion is largely a naming problem. The old term "hay fever" has no fever in it at all — it described the combination of sneezing, nasal symptoms, and general malaise that some people confused with a mild illness. The Mayo Clinic is explicit: allergic rhinitis does not cause fever.
If you have allergy-like symptoms — sneezing, runny nose, congestion — plus a measurable fever, the more likely explanations are:
A fever warrants attention from a healthcare provider, especially if it is high or accompanied by other symptoms such as severe headache or body aches.
Interest in alternative remedies for allergies is high, and while few have robust clinical evidence behind them, some have been studied enough to be worth discussing with a doctor. The Mayo Clinic notes that non-drug approaches can complement conventional treatment, though they should not replace proven therapies in people with significant symptoms.
Rinsing the nasal passages with a saltwater solution (using a neti pot or squeeze bottle) physically removes pollen and mucus from nasal membranes. It is safe, inexpensive, and supported by evidence as a helpful add-on for nasal allergy symptoms. Using distilled or sterile water is important to avoid introducing contaminants.
Butterbur (Petasites hybridus) is an herbal extract that has shown some benefit in small studies for relieving hay fever symptoms. The ACAAI notes that some research suggests it may perform comparably to antihistamines in limited trials, but evidence is not yet conclusive. Raw or unprocessed butterbur contains compounds that can be harmful to the liver, so only certified PA-free (pyrrolizidine alkaloid-free) extracts should be used, and use should be discussed with a doctor.
Quercetin is a plant flavonoid found in onions, apples, and tea that has been proposed to stabilize mast cells and inhibit histamine release. Laboratory evidence is promising, but well-designed clinical trials in humans are limited. It is generally considered safe at typical supplement doses but is not a proven substitute for medication.
The theory that consuming local honey gradually desensitizes the body to local pollen is widely shared, but clinical evidence does not currently support it as an effective allergy treatment. Pollen in honey is primarily flower (entomophilous) pollen, while allergy-triggering pollen is mainly wind-borne (anemophilous) from grasses, trees, and weeds — different types than what bees typically collect.
While not a dietary remedy, high-efficiency particulate air (HEPA) filters in home HVAC systems or portable air purifiers meaningfully reduce indoor airborne pollen and mold concentrations. The NIH/NIEHS recommends reducing indoor allergen load as part of a comprehensive allergy management plan.