A Cold vs. The Flu: How to Tell the Difference
The flu is running rampant this season. How do you distinguish it from its less perilous cousin, a cold? Symptoms often overlap, so when should you be concerned?
Last week, the CDC reported that the flu death count of children so far this season has reached a high of 30. The most prevalent strain this year seems to be the H3N2, and is now widespread throughout the country. The flu is particularly threatening to the elderly and children, tragically killing up to 50,000 people in the U.S. each year alone.
Winter also brings a slew of common cold viruses which are not nearly as perilous. But the symptoms often overlap with the flu. So how do you know when it’s a cold and when it’s the flu? How do you know when you should be more concerned?
What is a Cold?
The common cold is, well…more common. It is caused by a virus that is transmitted through touch or most commonly via air droplets (via the coughing or sneezing of someone plagued with it). It is self-limiting, meaning that it resolves on its own through time. But fortunately it is rarely deadly.
People experience the following symptoms:
- Mild fatigue
- Sore throat
- Runny/stuffy nose (the hallmark of the common cold)
- Cough
- Mild fever (but, more typically, no fever at all)
Check out this useful graph (via the American Rhinologic Society) depicting the course of a typical virus. Understanding this graph will help relieve any concerns about what is the normal and expected progression of a typical virus.
The common cold virus often begins as a sore throat, malaise, perhaps a mild fever (although usually none) on day one and gradually progresses to a runny and stuffy nose by day three or so, when the sore throat tends to resolve. The nasal symptoms are the most prominent and annoying feature in the common cold. As I often tell my patients, it causes a significant amount of fluid buildup in the face, resulting in symptoms like congested nasal passages, plugged ears, and a postnasal drip.
The typical common cold virus worsens each day after onset, then gradually peaks sometime between day three and five. After the peak, patients gradually improve with each day. Most people feel much improved sometime between day seven and ten.
But once plagued with the cold, all of that fluid built up has to go somewhere. So how does it exit the face? Down and out through the nostrils, or down the throat where it is swallowed (aka postnasal drip). Sorry to break it to you, but no matter how gross it seems to swallow snot, it happens to each and every one of us. That postnasal drip irritates the throat and causes a cough. Have you noticed that your cough may be waking you up at night? This is due to gravity pulling the drainage down the throat when lying down. Move the head of the bed up if this is happening to you. This exiting process can take weeks until the fluid has fully drained. This is why that nasal discharge and cough can linger on way past day seven to ten for some people.
What is the Flu?
The flu, or “influenza,” is also a virus but one that is much nastier, carrying a risk of some serious complications. Here are the symptoms of the flu:
- Higher fevers (typically over 101, may last up to 5 days)
- Severe fatigue (often described as a feeling of being “hit by a truck”)
- Body aches
- Sore throat
- Mild nasal symptoms or none at all
- Cough
- Nausea/vomiting/abdominal pain
Note the differences between a typical cold and flu virus. First, the onset of the common cold is gradual, yet it is rather sudden in the flu. Also, the fever and fatigue are much more prominent with the flu than with the common cold virus. The cold also doesn’t cause body aches typically. And unlike the flu, the nasal symptoms are a prominent feature of the cold whereas they are minimal or absent with the flu.
The common cold is no picnic, but people tend to feel dreadful with the flu when compared to the common cold virus.
Flu Complications
Pneumonia is the top complication of the flu virus. It is also one of the leading causes of death in hospitalized elderly. It can interfere with breathing, and we need oxygen to live. Besides elderly and children, the CDC has a comprehensive list of those people who are most at risk for developing pneumonia, including asthmatics and diabetics.
Myocarditis (inflammation of the heart) or pericarditis (the inflammation of the lining of the heart) are also risks of the flu, albeit less common.
When to Be Concerned
So if you or your children have now contracted the flu, when should you be worried? Here are the symptoms you never want to mess with:
- Any trouble breathing
- Using chest and abdominal muscles to work harder to breath (called “retractions”)
- Turning purple or blue (referred to as “cyanosis”)
- Confusion
- Inability to lower the fever using OTC meds
- High fevers
- Chest pain
- Signs of dehydration, such as dizziness upon standing or inability to keep fluids down
- Uncontrollable vomiting
In kids, besides the above, they should be seen right away if they experience:
Any possible risk of the vaccine is minute compared to the risk of the flu and the havoc it wreaks.
- Irritability to the point of being inconsolable
- Not easily wakened
- No tears or urine (signs of dehydration)
- Rash
Treatment of the Cold or Flu
There is no cure for either—its discovery will surely make some scientist rich one day. Why is it so difficult to find a cure? Because these sneaky viruses mutate rapidly—it’s not easy to attack it when it keeps changing its appearance. You can simply treat the symptoms until the virus has taken its course. Check out my prior article on treatment of viruses.
Oh, and antibiotics don’t touch viruses; they only fight bacteria. Oseltamivir (Tamiflu), an anti-viral medication, can be prescribed for some with the flu. Its effect on the flu virus is modest, possibly diminishing the severity and shortening the duration by one day only. Note that it is not as effective if taken past 48 hours of onset.
Thankfully, there is a vaccine for the flu. Is it perfect? No. And that’s again due to the swift mutation of these devious bugs. When devising the vaccine, scientists extrapolate the most common strains that are headed our way and then create a vaccine to destroy it. Let me tell you, even partial protection against the flu is better than none. Most people who die are not vaccinated.
Knowing what I know and what I’ve seen with what the flu can do, I will share with you that I, my two kids, and my husband—along with every other physician I know—are first in line to get vaccinated in September when the shot is made available. I would never harm my children and wouldn’t even for a second hesitate to vaccinate them. Any possible risk of the vaccine is minute compared to the risk of the flu and the havoc it wreaks. It is also the only good way we can halt its spread to others. Think of your elderly grandparents, or the children in your lives. For those of you who tell me that you “just don’t ever get sick,” vaccinating yourself not only protects you, but protects those around you.
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Please note that all content here is strictly for informational purposes only. This content does not substitute any medical advice, and does not replace any medical judgment or reasoning by your own personal health provider. Please always seek a licensed physician in your area regarding all health related questions and issues.
Image of sick man © Shutterstock
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About the Author
Dr. Sanaz Majd is a board-certified Family Medicine physician who graduated from Drexel University College of Medicine in Philadelphia. Her special interests are women’s health and patient education.
