For as long as there have been people living on the earth, there have been colds and influenza (the flu), viral infections that seem to come on as summer changes to fall and stay as unwanted guests throughout the winter. Chilly weather, the need to spend more time inside, children bringing viruses from home to school and back, and the increased stress of the holiday time can contribute to the situation.

Usually, a cold produces nasal congestion, sneezing, a sore throat, and coughing. A slight fever and blocked sinuses may also be associated with the condition. Flu has a tendency to come on suddenly with a fever as high as 104 degrees F, bad headaches, and muscle aches. It is sometimes accompanied by a dry, hacking cough.

While there is no cure for the cold, it has been found that certain herbal medicines can help the immune system work to defeat these viruses. The amount to be used should be based on a person's size, age, and conditions including certain allergies or pregnancy. Some of the herbal remedies include:

- Astragalus (Astragalus membranaceus) Chinese and American research has found that this member of the pea family will increase most activity within the immune-system. Typically, an adult would take 9 to 15 grams of the dried root daily for about one month as part of a decoction before cold and flu season. No side effects or contraindications have been reported with astragalus.

- Schisandra (Schisandra chinensis)
This is a vine whose name means "five-flavor berry" in Chinese. The berries are said to help the body produce fluids and to control coughing. Schisandra is also used as a stress reliever and to stop diarrhea. Adults generally take 6 to 9 grams of the dried fruit in a daily decoction or take 15 to 30 drops of the tincture two times a day for 30 days. Schisandra apparently has no side effects or contraindications.

- Echinacea (Echinacea angustifolia, E. pallida, or E. purpurea)
Echinacea, or purple coneflower, is said to be the best herb to take in the early stages of a cold or flu. It apparently stimulates the production of white blood cells, which are used by the body to fight infection. An adult would take 900 milligrams of the dried, powdered root daily, about 40 drops of the extracted liquid every two hours for about two weeks. Those who are allergic to flowers of the daisy family may experience side effects.

- Garlic (Allium sativum)
Besides helping to prevent colds and flu, garlic also helps stimulate the circulation, lower blood pressure, and aid in digestion. It is said to be a natural antibiotic. An adult would take 4 grams of fresh garlic daily, or one capsule twice a day during a cold. Garlic may also slow the clotting of blood so those who take anticoagulants should be careful. Eating too much garlic may also cause heartburn and flatulence.