Today, almost everyone with allergies ingests a substance called

antihistamine which ameliorates the allergic symptoms and other commonailments like cough, travel sickness, and cold symptoms. The substance first popularized in the 1950s, has become an invaluable medicine cabinet mainstay,providing relief for sinus headaches, allergic rashes, itchy skin, hay fever, hives, vertigo,and eveninsomnia.

Produced in the year of the baby boomer, antihistamines have provided help to people who have difficulty in sleeping as the substance can cause sleepiness. For instance, a drug called Nytol, which is an over-the-counter sleep aid,

contains the antihistamine substance called diphenydramine that causesdrowsiness and invokes sleep.

The mechanism of how antihistamines function inside the body is quite

simple. As the immune system recognizes foreign substances that enter and might harm the body, the "immune response" sets in to protect the body by killing off the offending "harmful" substances. Basically, the chemical histamine responds to a foreign substance and sends a signal to nearby cells that in turn activates these cells to launch the defense. But people who are allergic have an overactive "immune response" regarding something as harmful even when it's

not. And thus histamine is mistakenly released to protect the body from then so-called harmful substances.

Drugs containing antihistamines counter the action caused by histamine being released to cells and therefore ease the symptoms of allergic reactions.

Products containing antihistamines come in various forms? capsules, tablets,syrups, nasal sprays, eye drops, injections, creams and lotions? but before taking any medication, it is advisable to consult a doctor or pharmacist especially for pregnant or lactating women.