Flu or Cold Symptoms?

When you wake up sneezing, coughing, and have that achy, fever, can't move a muscle feeling, how do you know whether you have flu or cold symptoms?

It's important to know the difference between flu and cold symptoms. A cold is a milder respiratory illness than the flu. While cold symptoms can make you feel bad for a few days, flu symptoms can make you feel quite ill for a few days to weeks. The flu can also result in serious health problems such as pneumonia and even hospitalizations.

What are common cold symptoms?

Cold symptoms usually begin with a sore throat, which usually goes away after a day or two. Nasal symptoms, runny nose, and congestion follow, along with a cough by the fourth and fifth days. Fever is uncommon in adults, but a slight fever is possible. Children are more likely to have a fever with a cold.

With cold symptoms, your nose teems with watery nasal secretions for the first few days. Later, these become thicker and darker. Dark mucus is natural and does not usually mean you have developed a bacterial infection, such as a sinus infection.

Several hundred different viruses may cause your cold symptoms.

How long do cold symptoms last?

Cold symptoms usually last for about a week. During the first three days that you have cold symptoms, you are contagious. This means you can pass the cold to others, so stay home and get some much-needed rest.

If cold symptoms do not seem to be improving after a week, you may have a bacterial infection, which means you may need antibiotics.

Sometimes you may mistake cold symptoms for allergic rhinitis (hay fever) or a sinus infection. If your cold symptoms begin quickly and are improving after a week, then it is usually a cold, not allergy. If your cold symptoms do not seem to be getting better after a week, check with your doctor to see if you have developed an allergy or sinusitis.

What are common flu symptoms?

Flu symptoms are usually more severe than cold symptoms and come on quickly. Flu symptoms include sore throat, fever, headache, muscle aches and soreness, congestion, and cough. The flu is caused by a variety of influenza viruses.

Most flu symptoms gradually improve over two to five days, but it's not uncommon to feel run down for a week or more. A common complication of the flu is pneumonia, particularly in the young, elderly, or people with lung or heart problems. If you notice shortness of breath, you should let your doctor know. Another common sign of pneumonia is fever that comes back after having been gone for a day or two.

Just like cold viruses, flu viruses enter your body through the mucous membranes of your nose, eyes, or mouth. Every time you touch your hand to one of these areas, you could be infecting yourself with a virus, which makes it very important to keep your hands germ-free with frequent washing to prevent both flu and cold symptoms.

Is it flu or cold symptoms?

How do you know if you have flu or cold symptoms? Take your temperature, say many experts. Flu symptoms often mimic cold symptoms with nasal congestion, cough, aches, and malaise. But a common cold rarely has symptoms of fever above 38°C. With flu symptoms, you will probably have a fever initially with the flu virus and you will feel miserable. Body and muscle aches are also more common with the flu. This table can help determine if you have cold or flu symptoms.

When do I call the doctor with flu or cold symptoms?

If you have flu or cold symptoms, it's important to call your doctor if you have any of the following severe symptoms:

• Difficulty breathing or chest pain: These could be signs of more serious problems, including pneumonia, asthma, or even a heart problem.
• Persistent fever: This can be a sign of another bacterial infection that should be treated.
• Severe headache: This could indicate meningitis, an inflammation of the lining of the brain.
• Vomiting or inability to keep fluids down: If you are vomiting frequently, you may be at serious risk of dehydration, which means there isn't enough fluid in your body to get blood to your organs.
• Painful swallowing: Although a sore throat from a cold or flu can cause mild discomfort, severe pain could mean strep throat, which requires treatment by a doctor.
• Persistent coughing: When a cough doesn't go away after two or three weeks, it could be bronchitis, which may need an antibiotic. Postnasal drip or sinusitis can also result in a persistent cough. In addition, asthma is another cause of persistent coughing. Asthma medications such as steroids, anti-inflammatory medications, and bronchodilators are necessary to treat asthma.
• Persistent congestion and headaches: When colds and allergies cause congestion and blockage of sinus passages, they can lead to sinus infection. If you have pain around the eyes and face with thick nasal discharge after a week, you may have a bacterial infection and need an antibiotic.

Can I prevent flu or cold symptoms?

In addition to washing your hands often to help prevent flu or cold symptoms, getting a flu shot each year to prevent influenza is very important. Flu activity in the United States generally peaks between late December and early March, so Canada’s National Advisory Committee on Immunization (NACI) recommends getting a flu shot in October or November. Within two weeks of getting a flu shot, antibodies develop in your body and provide protection against flu symptoms.

If you do get flu symptoms, call your doctor. If you take prescription antiviral drugs within the first 48 hours of flu symptoms, the medications may help shorten recovery time. Antivirals may also help prevent the flu if you have been exposed to someone with flu symptoms.

WebMD Medical Reference

Sources:
FDA: Colds and Flu: Time Only Sure Cure.
American Lung Association: A Survival Guide for Preventing and Treating Influenza and the Common Cold.
Centers for Disease Control and Prevention: Questions and Answers: Cold versus Flu.
National Jewish Medical and Research Center: Is It a Cold or the Flu?
UpToDate: Clinical Manifestations and Diagnosis of Influenza in Adults.
UpToDate: The Common Cold in Adults: Diagnosis and Clinical Features.

Reviewed by Brunilda Nazario, MD on Sept. 17, 2007
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