Colds usually last about a week. When your runny nose and watery eyes last for more than two weeks, you probably have an allergy. Some 35 million Americans suffer from allergies to everything from cat hair to peanuts. The most common allergy is hay fever, a broad term used to describe the runny nose and eye irritation caused by a reaction to pollen, ragweed trees, or molds. Antihistamines and decongestants offer effective relief for many people.
Antihistamines work by blocking the release of histamines that bring on the allergy symptoms.
In the past antihistamines, often had a number of unpleasant side effects including sleepiness or hyperactivity, depending on the person. Some recently developed antihistamines work without crossing into the brain and so avoid many of the unwanted side effects. Decongestants offer relief of nasal and sinus congestion by narrowing blood vessels. Most decongestants are also stimulants, however, and may cause sleeplessness, nervousness and hyperactivity. A few adjustments to your daily routine may bring some relief from hay fever.