Cold/ allergies Cold/ allergies
 

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

 

Characteristic

Cold

Allergy

Duration

three-14 days

Days to months -- as long as you are exposed to the allergen

Time of Year

Most often in the winter, but possible at any time

Any time of the year -- although the appearance of some allergens are seasonal

Onset of symptoms

Symptoms take a few days to appear after infection with the virus.

Symptoms can begin immediately after exposure to the allergen

Symptom

Cold

Allergy

Cough

Often

Sometimes

Aches

Sometimes

Never

Fatigue

Sometimes

Sometimes

Fever

Rarely

Never

Itchy, watery eyes

Rarely

Often

Sore throat

Often

Sometimes

Runny or stuffy nose

Often; usually yellow mucus

Often; usually clear mucus

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.

There is no cure for either the common cold or allergies. But there are ways to ease the cold and allergy symptoms.

To treat either cold or allergy symptoms, you can try:

  • Antihistamines , which block the effects of histamine, a natural substance that causes symptoms such as congestion and a runny nose
  • Decongestants, which reduce swelling in the mucus membranes of the nasal passages, making you feel less stuffy

If you have any medical problems, or take other medicines, talk to your doctor before taking any over-the-counter medicines.

To treat allergy symptoms, your doctor may prescribe:

  • Nasal steroids, which reduce swelling in the nasal passages, relieving congestion and other symptoms
  • Allergy shots, called immunotherapy, which involves being injected with a small amount of the substance to which you are allergic. Over time, the dose is increased. By exposing you to greater and greater amounts of the allergen, your body may develop a tolerance to it and not cause symptoms.

To treat cold symptoms, you may also try:

  • Taking over-the-counter nonsteroidal anti-inflammatories, such as Advil or Aleve, or Tylenol, to treat fever, aches and pains
  • Getting extra rest
  • Drinking plenty of fluids

Although cold and nasal allergy symptoms are rarely serious, they can sometimes lead to other problems. For instance, both colds and allergies can lead to sinus infections. Colds may also lead to a middle ear infection. If you think you might have allergies -- or your cold symptoms seem severe or are not getting better -- see your doctor.