Is it a cold or the flu? How to tell and what to do

January 3, 2020

By Dr. Nick Harper, Clark Primary Care

Despite the joy in the air around the holidays, we are all more susceptible to the common cold and influenza from the late fall to early spring each year. I want to outline a few important items to keep in mind should you or someone you care for show signs of either.

First of all, it is important to differentiate influenza, or “the flu,” from a common cold. Both are caused by viruses, but the flu is caused by the influenza virus. The common cold can be caused by a number of potential viruses, the most common of which is likely rhinovirus.

The influenza virus tends to cause a more severe illness and starts more abruptly than the common cold. The flu tends to be more systemic in its effects with symptoms ranging from high fevers, chills, body aches, headaches, upper and/or lower respiratory symptoms (i.e. nasal congestion or cough and wheezing), and potentially even gastrointestinal symptoms like nausea, vomiting, and/or diarrhea. The high fever tends to be the hallmark sign that someone may have the flu rather than the common cold, but this is not always the case. There are many over-the-counter items that contain medications like Tylenol or Motrin, which can suppress fever even if that wasn’t the original intention.

Some populations are more susceptible to flu and may have more severe consequences. These populations include people over 65, very young children, individuals with weakened immune systems (such as cancer patients on chemo or people on certain types of therapy for autoimmune conditions), and people with chronic respiratory conditions such as COPD and asthma.

The cold tends to cause similar issues but to lesser extremes; however, the same populations that may have more severe cases of flu can also have serious consequences of a common cold. See the illustration from the Center for Disease Control for the most common specific differences between a cold and the flu.

Now that you can more easily recognize the difference between a cold and the flu, let me provide some tips for getting control of symptoms as early as possible. (Please do not consider these recommendations as a one-size-fits-all guide or substitute for your primary care provider’s instructions.)

Because both illnesses are caused by viruses and tend to have similar symptoms, we treat them in similar ways. Antibiotics are generally not helpful in treating cold or flu because antibiotics do not treat viruses, only bacteria. With that said, doctors may prescribe an antiviral for a confirmed or highly suspected case of influenza if it is diagnosed within 48 hours of symptom onset or if the individual has risk factors for a more severe case of flu. It is relatively rare to confirm flu in this window, and the antivirals do not have much benefit after 48 hours.

Also, occasionally the disruption of the body’s normal maintenance and function of the upper and/or lower respiratory tract by a cold or flu can allow a bacterial infection to closely follow, such as a sinus infection or pneumonia. Complications like this would then warrant using antibiotics. In general, providers try to limit unnecessary antibiotic use unless suspicion of a bacterial infection is very high so as to not contribute to the antibiotic resistance problem we are seeing with many bacteria. Providers also do not want to subject patients to the risks of side effects from antibiotics when they are not necessary.

Things that you may be able to safely do, and that I encourage my patients to do when I suspect a cold or flu, are to utilize the available and appropriate over-the-counter products to treat their symptoms so as to get them feeling better faster. For nasal congestion, nasal drainage, and even postnasal drip (mucus running from the upper nasal cavity down the back of the throat), I’ll suggest a nasal steroid spray like Flonase or Nasacort (generic versions for any of these products are encouraged due to lower cost and same efficacy), as well as an oral daily antihistamine pill like Zyrtec or Claritin.

In addition, a nasal lavage device like the different Neti Pot devices can work wonders in improving congestion and physically clearing allergens and viral particles sticking to the inner nasal cavity walls. Mucinex and similar products can be helpful in thinning mucous to make it drain easier or be coughed up more easily from the chest. Be sure to drink plenty of water with Mucinex to ensure appropriate thinning of mucous and avoid dehydration.

Be cautious with decongestant products like Sudafed due to the risk of blood pressure and heart issues. I always advise discussing with your doctor before using. Afrin nasal spray is another product that can cause issues due to what is called “rebound congestion” with overuse, so I also advise talking to a doctor before using.

In general, a lot of the other cold and flu products at your local pharmacy should be safe for short-term use, but they may not be any more effective than the aforementioned items.

Rest and good hydration are always key in the recovery process. If you have certain chronic conditions or are in a more susceptible age group, you should call your doctor for an appointment or at least specific advice on how to manage your symptoms.

On a final note, measures to prevent illness before it happens are always good practice. I highly recommend that everyone receive a flu shot unless someone has a significant contraindication. Use good hand hygiene practices in the home/work/community settings. And protect yourself as best as possible, whether with use of a hospital mask or avoidance of large crowds, especially if you have risk factors for a more severe case of cold or flu.