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As the Summer of Love approached in 1969, an English Invasion band named The Zombies was climbing the billboard charts with The Time of the Season.

What's your name?

Who's your daddy?

Is he rich like me?

Has he taken any time

To show you what you need to live?

Now fast forward to March 2007. The Zombies have long since gone their separate ways; and those particular lyrics about free love take on a whole new meaning in the pollution-ridden world of the 21st Century.

If you are one of the 26.1 million Americans suffering from allergies – free love or a sugar daddy is the least of your worries this season. What ‘you need to live’ if you or a family member suffers from seasonal allergies, is what to look for in over-the-counter allergy medications.

An allergy, in simplest terms, is a hypersensitivity to a substance in the environment. In the case of seasonal allergies, the chief culprit is pollen from grass, trees and ragweed. However, people who are allergic to pollen are usually sensitive to other allergens, including:

- Dust mites - microscopic insects that feed on human skin cells

- Animal dander - tiny skin flakes shed by animals

- Molds

When a hypersensitive body comes into contact with one of these substances, it produces an antibody called immunoglobulin E (IgE) in the intestines and lungs. IgE alerts the immune cells to release several chemicals, one of which is histamine.

Histamine is the culprit for watery eyes, runny nose, sneezing, and itching. That is why the most common type of over-the-counter allergy remedy contains an antihistamine. Antihistamines prevent histamines from causing symptoms.

According to the American Academy of Family Physicians, there are two types or “generations” of over-the-counter antihistamines:

First Generation

Second Generation

The reason for the distinction between the two generations of antihistamines has to do with side effects and whether or not an individual can safely take them if other health conditions are present.

First-generation antihistamines tend to make you feel drowsy. That is why products containing these antihistamines carry a warning label to avoid driving or operating machinery when taking them. They can also make it hard for you to think clearly, and can make your mouth and eyes feel dry. Second-generation antihistamines are less likely to cause these side effects.

Allergy sufferers with the following health conditions should consult their doctor before using a first-generation antihistamine:

-Glaucoma

-Trouble urinating because of an enlarged prostate

-Breathing problems, such as asthma, emphysema or chronic bronchitis

-Thyroid disease

-Heart disease

-High blood pressure

Individuals who have had kidney or liver disease should talk to their doctor before taking a second-generation antihistamine.

The next type of over-the-counter treatment recommended for seasonal allergy sufferers is nasal decongestants. Decongestants make blood vessels narrow, which reduces the blood flow to the mucous membranes that line the inside of the nose. This alleviates stuffy and runny noses.

Keep in mind you can only use a nasal decongestant spray for a few days. If you use it for a prolonged period of time, your nasal congestion may actually get worse. Using a nasal decongestant continually to avoid congestion can also cause dependence on the medication.

The most common types of nasal decongestant are:

  • Cromolyn (Nasalcrom) Cromolyn is what is known as a “mast cell stabilizer.” It works by stabilizing the immune system's mast cells, stopping them from releasing histamines when they encounter allergens. This type of decongestant is designed for long-term use.

Since nasal decongestant sprays only affect blood vessels in the nose and not in other parts of the body, they rarely cause any side effects.

Another typical symptom of seasonal allergies is allergic conjunctivitis, or red, watery eyes. You can relieve it by using eye drops that have a:

- Decongestant (Visine, Naphcon)

- Decongestant/anti-histamine combination (Visine-A, Naphcon-A)

Decongestant eye drops are only intended to be used for short periods of time. Overuse can lead to conjunctivitis medicamentosa, which results in severe eye redness, congestion and dependence on the eye drops. These eye drops should not be used by people with glaucoma. Individuals with heart or blood pressure problems should consult a physician before administering these types of drops.

The Food and Drug Administration has just approved ketotifen eye drops for over-the-counter use. Until now, ketotifen eye drops were only available with a prescription. These drops incorporate anti-histamine activity with prevention of the release of chemicals from mast cells.

Unlike decongestant eye drops, ketotifen should not result in conjunctivitis medicamentosa with long-term use. It is expected to be available by late spring 2007 under the brand name Alaway.

If it’s the time of the season for you or a loved one, you can find relief for the symptoms of seasonal allergies at your local drug store. However, if you have any existing medical conditions, or if you are taking any prescription drugs, talk to your doctor to be sure that these over-the-counter medications are right for you. Even though you can just grab it off the shelf, you still need to exercise the same caution as when you take prescribed medications of any kind.

Click here to visit FoxNews.com's Allergy Center

FoxNews.com health writer Maria Esposito contributed to this report.

For more great information on living healthy through every decade of life, click here to check out Dr. Manny's book The Check List (Harper Collins, 2007).

Dr. Manny Alvarez is the managing editor of health news at FOXNews.com, and is a regular medical contributor on the FOX News Channel. He is chairman of the Department of Obstetrics and Gynecology and Reproductive Science at Hackensack University Medical Center in New Jersey. Additionally, Alvarez is Adjunct Professor of Obstetrics and Gynecology at New York University School of Medicine in New York City.