本文发表在 rolia.net 枫下论坛There is no cure for allergies, but there are several types of medicines available -- both over-the-counter and prescription -- to help ease annoying symptoms like congestion and runny nose. These include antihistamines, decongestants, combination medicines, corticosteroids, and others.

Allergy shots, which gradually increase your ability to tolerate allergens, are also available.

Antihistamines

Antihistamines have been used for years to treat allergy symptoms. They can be taken as pills, liquid, nasal spray, or eye drops. Over-the-counter antihistamine eye drops can relieve red itchy eyes, while nasal sprays can be used to treat the symptoms of seasonal or year-round allergies.

Examples of antihistamines include:

Over-the-counter:
Benadryl, Claritin, Reactine

Prescription:
Allegra, and Atarax,

How Do Antihistamines Work?

When you are exposed to an allergen -- like ragweed pollen -- it triggers your immune system to go into action. Immune system cells in your nose and sinuses then release a substance called histamine, which attaches to receptors in blood vessels located in nasal tissues, causing them to enlarge. Histamine also binds to other receptors located in nasal tissues, causing redness, swelling, itching, and changes in nasal secretions. By blocking histamine receptors, antihistamines prevent these symptoms.

What Are the Side Effects?

Many over-the-counter antihistamines cause drowsiness. Non-sedating antihistamines are available by prescription.更多精彩文章及讨论，请光临枫下论坛 rolia.net