Influenza vs the Common Cold: Symptoms and Treatment

Brian Decker, PharmD Candidate, and Mark Herring, PharmD
Published Online: Wednesday, November 16, 2011

For additional perspectives relating to the topic, this article contains Clinical Commentaries from practicing pharmacists. To go directly to these commentaries, please click here or here.

Patients may find it difficult to distinguish between a cold and the flu, and pharmacists can help them determine if self-treatment is appropriate.


Having a cold or the flu is a familiar event for many of us. A cold usually comes on slowly, starting with a runny or stuffy nose, sneezing, and a sore throat. The flu often comes on quickly with extreme tiredness, fever, body aches, and a cough. Both usually last for 1 to 2 weeks. The symptoms are similar and difficult to tell apart. The flu is typically worse than a cold and more likely to cause complications that require prescription medications or hospitalization.

How Do I Know If It Is a Cold or the Flu?

The flu and the common cold are respiratory illnesses caused by different viruses. There are hundreds of cold viruses that can cause a cold any time of year. There are fewer flu viruses. The main 2 types are influenza A and B.

Although the flu is most common during flu season, which lasts from October to mid-May, it can happen any time of year. Unfortunately, the flu and a cold cannot be reliably told apart by either the symptoms or the time of year.

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When Should I See a Doctor?

Complications of the flu and a cold include strep throat, pneumonia, bronchitis, sinus infections, and ear infections. Signs of these complications include a persistent fever (greater than 101°F for more than 3-4 days in adults), painful swallowing, persistent coughing (lasting longer than 3 weeks), persistent congestion, and headaches (lasting longer than 1 week). People with chronic health problems, such as obesity, asthma, diabetes, and heart disease, can have additional complications.

People at a high risk of developing complications should see their doctor if they have flu-like symptoms. Although there is no cure for the flu, a doctor can prescribe oseltamivir (Tamiflu) or zanamivir (Relenza). These antiviral drugs can lessen the severity and shorten the duration of the flu, thus reducing the likelihood of complications. These drugs are most effective if taken within 48 hours of the start of flu symptoms.

If complications are already present, the doctor can prescribe additional medications, such as antibiotics, or recommend hospitalization. The Centers for Disease Control and Prevention (CDC) lists the following groups as at high risk for developing complications:

• Children younger than 5 years, but especially children younger than 2 years

• Adults 65 years and older

• Pregnant women

• American Indians and Alaskan natives

• People who have chronic medical conditions

If your doctor prescribes medications to treat the flu, it is important to take the medicine promptly and properly. Take time to talk to your pharmacist about how to take the medications and what to expect. When treating the flu, either after seeing a doctor or on your own, the symptoms should begin to clear up within 1 week. If they do not, contact your doctor.

The CDC lists emergency warning signs to watch for that require immediate medical attention, especially for those in the high-risk groups.

Emergency Warning Signs

In Children:

• Fast breathing or trouble breathing

• Bluish skin color

• Not drinking enough fluids

• Not waking up or not interacting

• Being so irritable that they do not want to be held

• Flu-like symptoms that improve but then return with fever and worse cough

• Fever with a rash

In addition to the signs above, get medical help right away for any infant who has any of these signs:

• Unable to eat

• Trouble breathing

• No tears when crying

• Significantly fewer wet diapers than normal

• Younger than 2 months with fever of 100.4°F or higher

• 3 to 6 months old with fever of 103°F or higher

• Older than 6 months with fever of 104°F or higher

In Adults:

• Difficulty breathing or shortness of breath

• Pain or pressure in the chest or abdomen

• Sudden dizziness

• Confusion

• Severe or persistent vomiting

• Flu-like symptoms that improve but then return with fever and worse cough

When Should I Treat My Illness at Home?

If you are not in one of the high-risk groups for complications, you do not have any of the emergency warning signs, you are well enough to take care of your basic needs, and your symptoms are mild, you are most likely able to treat your flu or cold at home. If you are not sure, talk to your pharmacist or doctor.

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Self-Care for Cold and Flu

Getting plenty of rest and fluids is the first thing you can do to speed your recovery. It is best to avoid caffeinated beverages and alcohol, and instead focus on water, juice, and soup. Stay in bed, keep contact with household members to a minimum, and do not go out in public unless absolutely necessary. Caregivers should likewise keep contact to a minimum and wash hands often with soap and water.

Remember that during the first 3 days that you have cold symptoms, you are contagious. With the flu, you are contagious 1 day before symptoms develop and up to 5 to 7 days after becoming sick. Stay home for at least 24 hours after your fever is gone, except to get medical care.

Most symptoms can be treated with over-the-counter medications if they are getting in the way of sleep. The Table summarizes the common symptoms and their treatments. Again, take time to talk to your pharmacist about how to take the medications, read the package directions each time, and use only the supplied measuring device. Children younger than 6 years should take cough or cold medications only under the direction of a doctor. Children under the age of 19 years should never take aspirin.

How Can I AvoId GettIng The Flu or a Cold?

Good personal hygiene is important for preventing illness. Touching your face, mouth, nose, or eyes after contact with the virus provides an easy way in. Coughing and sneezing sends the virus into the air.

Using tissues, covering your mouth with the crook of your elbow, or even using a mask can reduce the spread of the virus. Getting vaccinated for the flu is one of the best ways to protect yourself and your community against the virus.

Who Should Get a Flu Shot?

Unless you are allergic to chicken eggs or had an allergic reaction to a flu shot in the past, everyone older than 6 months should be vaccinated. PT 


Mr. Decker is a PharmD candidate at the University of Eshelman School of Pharmacy, University of North Carolina at Chapel Hill. Dr. Herring is pharmacist in charge at CVS Pharmacy in Carrboro, North Carolina.



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