An Overview of the Common Cold & Flu

The words "cold" and "flu" are sometimes used interchangeably when they're actually quite different. Both illnesses can leave you feeling pretty lousy, but how can you tell the difference between each? And more importantly, how can you relieve your symptoms? 

About the Common Cold

On average, American adults will have two to four colds per year, and children will get between six and 10. The common cold is the most common illness in the United States today, and it is also the most common reason for doctor's visits, yet there is no cure for it.

Symptoms

The most common symptoms of a cold.

Cold symptoms typically last between seven and 10 days. Symptoms start out mild and then gradually worsen over the next few days. While a cold can leave you feeling pretty miserable, it typically isn't severe enough to interfere with your day-to-day activities.

Common symptoms include:

  • congestion
  • cough
  • runny or stuffy nose
  • itchy or watery eyes
  • sore throat
  • feeling tired
  • headache
  • fever (rarely—more common in children)

If your symptoms are much different than those listed above, you probably have another illness or infection.

Diagnosis

Most people do not go to the doctor to be diagnosed with a cold. Even if you do, it will be diagnosed based on your symptoms and physical exam, not by any specialized tests, although some tests may be run to rule out other causes for your symptoms. 

Treatment

Because colds are viral, they cannot be treated with antibiotics. Over-the-counter cold medicine may help relieve symptoms, but the only true "cure" is to let a cold run its course.

It will go away on its own within about a week. 

If you have ever walked down the "cold and flu" aisle at your local pharmacy or grocery store, you know there are a lot of medicines out there claiming to be the one that will make you feel better. It can be overwhelming and the truth is, none of them are going to cure you. Some of them may help bring you relief from your symptoms, but the only thing that will actually make them go away is time. Of course, that doesn't mean you shouldn't take any of them. We have a complete guide to cold medicine that can help you figure out which options are best for you and your symptoms. 

There are also medication-free ways to help yourself feel better when you have a cold (or the flu). Running a humidifier, rinsing your sinuses with saline, drinking extra clear fluids and getting extra rest can all help you feel better faster. 

About the Flu

The flu is caused by the influenza virus. There are many strains of influenza, and it frequently mutates, creating new subtypes and variants.

Although there are three main types of influenza—A, B, and C—only influenza A and B cause seasonal influenza symptoms. The CDC estimates that 5 to 20 percent of Americans come down with the flu annually. It can be a very serious infection that claims the lives of thousands of people each year.

Symptoms

A sore throat is a common symptom of both the cold and flu.

Cold symptoms usually start out relatively mild. You may feel a headache starting or have an itchy throat. In contrast, the flu hits you hard and all at once. Many people describe it as feeling like they "were hit by a truck." Although cold and flu symptoms can be similar, the symptoms of the flu are more severe and distinct. 

Flu symptoms include:

  • fever
  • headache
  • body aches
  • extreme fatigue
  • cough
  • sore throat
  • mild congestion—stuffy or runny nose
  • vomiting and/or diarrhea (this is uncommon in adults, occurs more frequently in children)

Diagnosis

If you think you might have the flu, seeking medical attention early may make a difference. There are tests that your health care provider can perform to determine if your symptoms are caused by influenza and antiviral medications that you may be able to take if you have it.

Certain people are at high risk for complications from the flu and should be started on treatment as soon as possible to prevent serious symptoms, complications, or hospitalization. Among those at highest risk are pregnant women, older adults, children under age 5 and people with chronic medical conditions such as heart disease, asthma, or diabetes. If you aren't sure whether or not your health condition puts you at high risk for flu complications, talk to your healthcare provider before you get sick, so you will have a plan if you develop flu symptoms. 

Treatment

The flu cannot be treated with antibiotics, but it can be prevented with the annual flu vaccine. Although flu vaccines are not 100 percent effective, they are the best protection we have against this virus. Antiviral medications can help shorten the duration of the flu if you get it and can help protect you from it if you are exposed to someone with the flu. These medicines are available by prescription only, so you'll have to see your healthcare provider to get them.

They are also only truly effective if started within the first 48 hours of the start of your symptoms. If you wait until you are on day three or four of your illness, they are unlikely to make a difference. 

In addition to prescription antiviral medicines, OTC cold and flu medicine may help relieve your symptoms as well. Taking a pain reliever/fever reducer such as Tylenol (acetaminophen) or Motrin (ibuprofen) can help with fever and many of the aches and pains that come with the flu. Decongestants and expectorants can help with coughing and congestion as well. Although these medicines won't cure your illness, they can help with the symptoms, so you don't feel quite as bad. 

How to Tell If It's a Cold or the Flu

Determining whether it's a cold or the flu doesn't have to be difficult. If you know what to look for, you can usually tell if you have a cold or the flu as soon as you notice symptoms. It's especially important to recognize the symptoms that are flu-like and notify your doctor within the first 24 hours. If you can take Tamiflu or another antiviral flu medication within 48 hours of the start of symptoms, the flu may be shorter or less severe. Just remember, if the symptoms hit you hard and fast, it's probably the flu. If they start slowly and then get gradually worse, it's more likely a cold. 

A Word From Verywell

No one is healthy all the time. Even the healthiest among us gets a cold from time to time. These germs are all around us and they are impossible to avoid. However, knowing what to expect and what to do when you get sick can help you recover as quickly as possible. 

Sources:

CDC. The Flu: What To Do If You Get Sick. Centers for Disease Control and Prevention. http://www.cdc.gov/flu/takingcare.htm. Published May 26, 2016.

Common Cold. http://www.niaid.nih.gov/topics/commoncold/Pages/default.aspx.

Key Facts about Influenza (Flu) | Seasonal Influenza (Flu) | CDC. http://www.cdc.gov/flu/keyfacts.htm.

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