What is hay fever? What are hay fever symptoms and signs?
Hay fever affects up to 30% of all people worldwide, including up to 10% of U.S. children under 17 years of age and 7.8% of U.S. adults. The medical cost of allergic rhinitis is approximately $3.4 billion, mostly due to the cost of prescription medications. These figures are probably an underestimate because many of those affected may attribute their discomfort to a chronic cold. Although childhood hay fever tends to be more common, this condition can occur at any age and usually occurs after years of repeated inhalation of allergic substances. The incidence of allergic disease has dramatically increased in the U.S. and other developed countries over recent decades.
"Hay fever" is a misnomer. Hay is not a usual cause of this problem, and it does not cause fever. Early descriptions of sneezing, nasal congestion, and eye irritation while harvesting field hay promoted this popular term. Allergic rhinitis is the correct term used to describe this allergic reaction, and many different substances cause the allergic symptoms noted in hay fever. Rhinitis means "inflammation of the nose" and is a derivative of rhino, meaning nose. Allergic rhinitis that occurs during a specific season is called "seasonal allergic rhinitis." When it occurs throughout the year, it is called "perennial allergic rhinitis." Rhinosinusitis is the medical term that refers to inflammation of the nasal lining as well as the lining tissues of the sinuses. This term is sometimes used because the two conditions frequently occur together.
Symptoms of allergic rhinitis, or hay fever, frequently include
- nasal congestion,
- a runny nose with clear mucus,
- nose, eye itching, and
- excess tear production in the eyes.
Postnasal dripping of clear mucus frequently causes a cough. Loss of the sense of smell is common, and loss of taste sense occurs occasionally. Nose bleeding may occur if the condition is severe. Eye itching, redness, and excess tears in the eyes frequently accompany the nasal symptoms. The eye symptoms are referred to as "allergic conjunctivitis" (inflammation of the whites of the eyes). These allergic symptoms often interfere with one's quality of life and overall health.
Many people with allergies have difficulty with social and physical activities. For example, concentration is often difficult while experiencing allergic rhinitis symptoms.