An allergy is an exaggerated abnormal immune response to something in the environment that normally would not be harmful. One of the most common types of allergies is the seasonal allergic rhinitis, or hay fever. Hay fever affects one in five people, according to MayoClinic.com, and causes many of the same symptoms as the common cold. Seasonal allergies are caused by airborne pollen from trees, grasses and flowers. Contact initiates the immune response, leads to inflammation of the blood vessels in the air passages and produces a variety of symptoms that are annoying, but rarely dangerous.
Symptoms of hay fever commonly affect the eyes. There is a tremendous volume of blood vessels in and around the eyes that can become inflamed and irritated. It is very typical for seasonal allergies to begin with itchy and watery eyes. As the irritation continues, a patient may rub or scratch the eyes in an attempt to relieve symptoms, which can aggravate them and cause them to become red. The conjunctiva is a membrane lining the eye and can become irritated, causing a condition called conjunctivitis, according to MedlinePlus. Many over-the-counter and prescription medications are available to help relieve eye symptoms associated with seasonal allergies.
An allergic reaction will often cause runny nose and congestion as the airway passages become inflamed and filled with mucus. Part of the immune response that occurs when the body encounters an allergen is the production of mucus. This thick fluid fills the sinuses and drains into the throat causing an array of irritating symptoms. According to PDRhealth.com, this congestion can also lead to headaches, coughing, wheezing and sneezing. Many people with seasonal allergies notice difficulty or impairment with their senses of smell, likely due to congestion build-up.
According to MedlinePlus, it is possible to have several different allergy symptoms occur in the abdomen. Some allergy sufferers develop stomach cramps, upset stomach and even vomiting.
PDRhealth.com lists sleep disturbance as one of the symptoms associated with hay fever. This is likely caused by the collection of other symptoms, such as coughing, sneezing, runny nose, congestion and headache, making it difficult for the sufferer to get good quality rest.
A 2008 report in "USA Today" states that for an increasing number of seasonal allergy sufferers, symptoms not usually associated with hay fever are becoming problematic. These symptoms include fatigue, irritability, mood changes and depression. The report notes that recent research suggests that allergic reactions cause feelings of depression and fatigue by releasing cytokines. These cytokines are chemicals that cause inflammation in an attempt to protect the body from the allergen, but react with other brain chemicals to cause abnormal feelings.