What is allergies (allergic rhinitis)?

Allergies happen when you are exposed to certain particles in the air (allergens). Your body's defense system (immune system) overreacts to certain substances. The immune system may treat a harmless substance as if it were a harmful germ or virus. Many things can cause this problem. You can be allergic to things such as pollens, dust, or animal dander.

Your allergies can be mild or severe. Mild allergies can be managed with home treatment. But medicine may be needed to prevent problems.

When allergies aren't treated, they can affect your health. You may have problems such as sinusitis, plugged ears, and ear infections. Allergies can also affect your quality of life. You may avoid seeing people, have problems sleeping, and feel tired or grumpy.

Allergy symptoms may start within minutes or hours after you breathe in an allergen. And the symptoms can last for days.

When symptoms start right away, you may sneeze over and over again. This often happens after you wake up in the morning. You may have a tickle in your throat or coughing caused by postnasal drip. Your nose may be runny. And your eyes may be watery and itchy. Your ears, nose, and throat may also be itchy.

Other symptoms may take longer to appear. For example, you may have a stuffy nose. You may feel pressure in one or both ears, or have pain in your face. Your eyes may be sensitive to light. You may also have a long-lasting cough. Some people notice dark circles under their eyes.

Your symptoms may be better or worse at different times of the year.

Your doctor can most often diagnose allergic rhinitis by doing a physical exam and asking you questions about your symptoms, activities, and home.

You may need allergy tests if:

• You and your doctor need to find out exactly what things you are allergic to. And then you can take steps to avoid them.
• Treatment is not helping your symptoms.
• You have severe symptoms.
• You are thinking about trying immunotherapy (such as allergy shots).

A skin test can show how your skin reacts to an allergen. Or a blood test can measure the level of antibodies that your body makes in response to certain allergens.

These tests can help your doctor know what is causing your symptoms and find the best treatment.

There are three main treatments for allergic rhinitis:

• Avoid the things you are allergic to (allergens). For example, you may need to clean your house often to get rid of animal dander. Or you may need to stay indoors when pollen counts are high.
• Manage your symptoms with medicine. Over-the-counter corticosteroid nasal spray, antihistamine or decongestant pills, or prescription nasal spray antihistamines may help relieve some of your symptoms.
• Get immunotherapy (such as allergy shots). For this treatment, you get shots or take pills that have a small amount of certain allergens in them. Your body "gets used to" the allergen, so you react less to it over time.

There are many things you can do to help your allergies.

Avoiding allergens

Avoid things that may cause your allergies. For example:

• Control animal dander and other pet allergens. One way to do this is to restrict pets to certain areas of your home.
• Avoid outdoor pollens. This may include staying inside while pollen counts are high.

It may be helpful to track your allergens and how long after exposure to them you start to have symptoms. You can keep a symptom diary to track this information.

Managing your symptoms

Symptoms are often managed with medicines. You can buy many types of allergy medicines without a prescription. Be safe with medicines. Read and follow all instructions on the label.

• Corticosteroid nasal sprays help reduce inflammation in the nose. They are available both over-the-counter and by prescription.
• Antihistamines help relieve sneezing, runny nose, itching, and watery eyes.
• Decongestants help relieve a stuffy nose.
• Eyedrops help relieve red, itchy, and watery eyes.