Pollen grains from trees, grasses and weeds can float through the air in spring, summer or fall. But along with staying on mission to fertilize plants and tree flowers, pollen particles often end up in our noses, eyes, ears and mouths. The result can be sneezing spells, watery eyes, congestion and an itchy throat. Pollen allergy, commonly known as hay fever, affects about 1 out of 10 Americans, according to the National Institute of Allergy and Infectious Diseases (NIAID). For some, symptoms can be controlled with occasional over-the-counter (OTC) medicine. Others have reactions that may more seriously disrupt the quality of their lives. Allergies can trigger or worsen asthma and lead to other health problems such as sinusitis and ear infections in children. You can distinguish allergy symptoms from a cold because a cold tends to be short-lived, results in thicker nasal secretions, and is usually associated with sore throat, hoarseness, malaise, and fever. Many people with seasonal allergic rhinitis notice a seasonal pattern with their symptoms, but others may need a doctor's help to find out for sure that pollen is the source of their misery. If these symptoms crop up year-round, dust mites, pet dander or another indoor allergen could be the culprit. This is known as perennial allergic rhinitis. Once you know you have seasonal allergies, probably the most important step you can take is to avoid pollen as much as possible. Try to stay indoors when pollen levels are highest. In the fall ragweed pollen season, pollen levels are highest in the morning. During the grass pollen season in the spring and summer, pollen levels are highest in the evening. Pollen counts measure how much pollen is in the air and are expressed in grains of pollen per square meter of air collected during a 24-hour period. It may also help to keep windows closed in your house and car and to run the air conditioner. If possible, avoid mowing grass and other yard work.

Some of the allergy symptoms that Zyrtec can reduce and eliminate are watery and itchy eyes, sneezing, congested nose, runny nose, and other nasal irritations.

Rhinitis is inflammation of the inner lining of the nose. Allergic rhinitis is characterized by an itchy/runny nose, sneezing, and nasal congestion. Other allergic symptoms include itchy ears and throat, Eustachian tube problems, red/watery eyes, cough, fatigue/loss of concentration/lack of energy from loss of sleep, and headaches or facial tenderness. Rhinitis can be either acute or chronic. Seasonal allergic rhinitis (also called hay fever) is usually caused by pollen in the air, and sensitive patients have symptoms during peak times during the year. Perennial allergic rhinitis, a type of chronic rhinitis is a year-around problem, and is often caused by indoor allergens, such as dust and animal dander. Symptoms tend to occur regardless of the time of the year. Non-allergic rhinitis (also called vasomotor rhinitis) occurs in those patients in whom an allergic cause cannot be identified. Vasomotor rhinitis is thought to occur because of abnormal regulation of nasal blood flow. Post-nasal drip is a mucous accumulation in the back of the nose and throat leading to or giving the sensation of mucus dripping downward from the back of the nose. Chronic rhinitis is characterized by persistent irritation and inflammation of the lining tissues of the nose. One of the most common characteristics of chronic rhinitis is post- nasal drip. Post-nasal drip may lead to chronic sore throat. Post-nasal drip can be caused by excessive or thick secretions or an impairment in the normal clearance of mucus from the nose or throat.

How do allergies develop : The immune system is the body's organized defense mechanism against foreign invaders, particularly infections. Its job is to recognize and react to these foreign substances, which are called antigens. Antigens are substances that are capable of causing the production of antibodies. Antigens may or may not lead to an allergic reaction. Allergens are certain antigens that cause an allergic reaction and the production of IgE. The aim of the immune system is to mobilize its forces at the site of invasion and destroy the enemy. One of the ways it does this is to create protective proteins called antibodies that are specifically targeted against particular foreign substances. These antibodies, or immunoglobulins are protective and help destroy a foreign particle by attaching to its surface, thereby making it easier for other immune cells to destroy it. The allergic person however, develops a specific type of antibody called immunoglobulin in response to certain normally harmless foreign substances, such as cat dander. To summarize, immunoglobulins are a group of protein molecules that act as antibodies.