Cold, Flu, & Cough Health Center

Is It a Common Cold or Allergies?

You've got a runny nose, a cough, and congestion. So have you caught a cold or is it allergies? Unfortunately, it's often hard to tell -- even for doctors. But here's information that may help. Read on to learn more about the causes and treatments of cold and allergy symptoms.

What Are Colds and Allergies?

Colds are caused by hundreds of different viruses. When one of these viruses gets into your body, your immune system attacks it. Some of the effects of this immune response are the classic symptoms of a cold, such as congestion and coughing.

The germs that cause colds are contagious. You can pick them up when an infected person sneezes, coughs, or shakes hands with you. After a couple of weeks, at the most, your immune system fights off the virus and you should stop having symptoms.

Allergies are caused by an overactive immune system. For some reason, your body mistakes harmless substances -- such as dust or pollen -- for germs and attacks them. Your body releases chemicals such as histamine, just as it does when fighting a cold. This can cause swelling in your nasal passages, a runny nose, coughing, and sneezing. Allergies are not contagious, although some people may inherit a tendency to develop them.

Differences Between Colds and Allergies

Although there are some differences, cold and allergy symptoms overlap quite a bit. The most important difference is that colds usually don't last longer than 14 days. If you still have symptoms after two weeks, see your doctor. These may be allergy symptoms or a sign of another problem.

Prevention and Treatment of Colds and Allergies

Because the causes of cold and allergy symptoms are quite different, preventing them requires different strategies.

To prevent allergy symptoms, avoid substances you're allergic to, called allergens. So if you're allergic to pollen, for instance, avoid going outside on days when the pollen count is high. Here are some common allergens:

• Pollen
• Mold
• Animal dander
• Dust mites
• Cockroaches

To prevent cold symptoms, prevent the cold-causing virus from getting into your system.  Keep your distance from people who have colds. Wash your hands often. To protect others, always cover your mouth and nose (with a tissue or your sleeve, rather than your hands) when sneezing or coughing.