Cold versus Flu

OK, we’re knee-deep in cold and flu season. As I sit here contemplating the difference between cold and flu, it strikes me that flu season has yet to hit us. So, if you’ve been sick so far this year, you’ve probably had the cold.

What is the “common cold”?  Well, it’s a viral infection, generally rhinovirus. Rhino…like the nose, not the animal (although the animal derives its name from the Greek word for nose due to the large nose-like proboscis on its head). So that can help you understand that the primary symptoms of colds are nasal symptoms. The first few days you feel tired and run-down.  Your throat starts to hurt. Then the nose starts to run and you sneeze. The nose then also becomes stuffy and congested.  It’s the stuffy and runny combination that if you really think about it is rather odd. How can something both be stuffed and running? That is more than I can say for Uncle Pat after Thanksgiving dinner! The interesting thing is that influenza (flu) also does that. The difference between the two is the intensity of symptoms.  Flu is a much more intense version of the cold.  Often, the mucous that is causing the congestion and runny nose causes a cough. I’d say easily, the cough is what brings people to the office when dealing with a cold.  It comes later in the course of illness and lasts beyond the time when you feel “sick."  You feel like the cold is gone but the cough can linger for weeks (yes, I said WEEKS).

One thing you may have noticed is that I did not mention fever. That’s because the cold doesn’t cause a fever. That’s not to say it won’t raise your body temperature, because it will. You just won’t have a fever.  So here’s a little tip. A temperature greater than 98.6 is NOT a fever. We refer to them as low-grade fevers but really they are not fevers. A fever starts when the temperature reaches 100.4. That seems like an odd number. It’s because scientific and global measurements are done with Centigrade temperatures. So that corresponds to 38C. Normal body temperature on that scale is 37. That one degree Celsius separates normal from febrile. So from 98.6 to 100.4 is not a fever. Why does it raise your temperature? Well, that’s because in fighting off this virus, your immune system gets activated. The T cells notice the virus and deploy a search-and-destroy call to other T cells.

Other symptoms include cough, congestion, fever (that one is almost a deal-breaker and without it, the flu is not really a consideration—so be sure to check your temperature…with a thermometer!), body aches, sore throat, and sometimes diarrhea. To remind you, the cold has those symptoms as well. The major difference is the sudden onset of the flu (all/most symptoms hit you at once, generally within 12 hours of each other) and the fever over 100.4. The colds all have the same basic symptoms but are generally more gradual in their onset (starts with a tickle in the throat for a day, then runny nose for a day, then cough…and lingers 10 days or more), are much less intense and often without that higher fever.

If you realize you have the flu and it’s been more than 48 hours of symptoms, available treatments aren’t going to work anymore. Even if we do treat these flu episodes, the medication has only been shown to shorten the length of time you’re sick by 1 day. So unless you have major medical conditions, specifically lung disease, we don’t automatically treat the flu with the anti-viral medicines because the side effects (on you, the patient) and the virus (it can make the virus mutate faster) aren’t always worth that 1 day of symptom improvement. We mostly focus our efforts on making you more comfortable while you are fighting this virus off. Once we know flu is in our area, we don’t typically test for it and treat you based on symptoms alone.

The good news is you don’t have to face this alone! Your healthcare provider at your PinnacleHealth Medical Group primary care office has you covered. If you feel you are sick and not sure if it’s the cold or the flu, ask one of the pros. It’s why we’re here, after all! Be well and stay well!!

Sandra R. Costa, DO, FAAFP

Heritage Family Medicine

Member, PinnacleHealth Medical Group