Cold vs. Flu ­– How to Recognize, Treat and Prevent Both

By Stephen T. Sinatra, M.D., F.A.C.C., F.A.C.N., C.N.S., C.B.T.

‘Tis the season to think about immunity…it’s time to protect against cold and flu. If you’ve got young children or grandchildren in school or day care, fly often or take public transportation to work or school, live in a nursing home, or work in a public place, your chances of catching the common cold or influenza (“the flu”) are pretty high. Hence, prevention is key (I’ll get to that below).

The viruses that cause colds and flu are completely different, but symptoms of the illnesses can be similar—and most would agree, pretty miserable. Here’s a breakdown of cold vs. flu symptoms.

Cold vs. Flu Symptoms

Both the common cold and the flu are transmitted two ways: person to person, usually through droplets in the air when a sick person coughs or sneezes; and by coming into contact with surfaces that have the viruses on them and then touching your eyes, nose, or mouth. Young children are especially adept at spreading such viruses through both means of transmission, though germs are known to spread pretty fast through offices too.

Symptoms of a cold can take up to three days to appear after exposure to the virus. The most common symptoms include:

  • Runny nose
  • Sore throat
  • Cough
  • Congestion
  • Sneezing
  • Watery eyes
  • Mild fatigue or tiredness

Influenza symptoms appear suddenly and are much more severe than those of the common cold. Another key difference between cold and flu is that most people develop a high fever with flu, which usually doesn’t happen with a cold. Other signs of flu include:

  • Severe muscle and joint aches
  • Dry, hacking cough
  • Sore throat
  • Runny or stuffy nose
  • Headache
  • Shaking chills
  • Profound fatigue that may last for up to two weeks
  • Occasionally, nausea/vomiting

While the common cold can be annoying, it won’t cause serious complications in most people. Not so with the flu. People most at risk of complications from the flu are babies and young children, pregnant women, adults over age 65, and people with compromised immune systems due to other medical conditions.

In particular, the flu can lead to secondary illnesses, such as pneumonia, dehydration, ear or sinus infections, and even life-threatening complications like sepsis or inflammation of the heart, brain, or muscles. The flu can also worsen chronic conditions like asthma, diabetes, and heart disease.

Given all this, protecting yourself should be top priority—especially if you are at higher risk for complications. So everyone should get a flu shot, right? Not so fast…

Boost Your Immunity Against Coronavirus

Flu Shot Effectiveness

Although many physicians believe that the best way to protect yourself from the flu is by getting a flu vaccination, I don’t agree. Flu shot effectiveness is not 100 percent, so even if you get the vaccine, there’s still a chance you can still get sick. Reason being, the flu shot’s formula is based on the three or four biggest strains that circulated around the world during the previous flu season. Thus, the experts can’t be sure that the vaccine will always work perfectly in the current season.

From my observation over the years those who have gotten shots experience colds and flu as much as people who have passed on them. Moreover, the research I’ve read clearly indicates that flu shot is not very effective.  A 2014 review involving 90 studies and more than 9 million people concluded that flu shots, “have a very modest effect in reducing influenza symptoms and working days lost in the general population…” The CDC estimated flu shot efficacy for the 2017 to 2018 flu season was 38 percent, and last year’s 2018 to 2019 flu shot was only 29 percent effective.

If you are at very high risk of serious complications from the flu, then a flu, or even pneumonia, shot may be right for you. But for the majority of the population, taking other measures to prevent flu and colds can be just as effective—oftentimes even more effective—than getting vaccinated, should you choose not to get a flu shot.

Prevent Cold or Flu by Strengthening Your Natural Defenses

When I used to see patients on a day to day basis in the office or hospital, many of them sick with cold or flu, I didn’t catch these bugs because I took steps to strengthen my immune system naturally, which I’ll tell you about here.

One of the best ways to prevent cold or flu is to regularly and thoroughly wash your hands (using warm water and plain old soap). This is especially important after touching doorknobs, light switches, toilet handles or any other surfaces that are shared or used by many people. Your hands might get pretty dry, but applying hand lotion more often is preferable to being sick, right? Also be sure to avoid touching your eyes, nose, and mouth – even with clean hands. Wash kids’ hands more often too. You’ll be that much better off.

However, since cold and flu viruses are also spread through the air (the flu virus can travel up to six feet!), unless you hole yourself up at home or in a protective bubble all season, it’s hard to completely avoid exposure. All the more reason to fortify your defenses from the inside out…

  • Lifestyle. Make sure you get plenty of shuteye every night, since sleep bolsters your immune system. Eat right – more fresh fruits and vegetables and less sugar and alcohol – and exercise regularly. Stay hydrated (at least eight glasses of water per day), because dry mucous membranes in your mouth, nose, and throat make it easier to viruses to attach and infect your body.
  • Take antioxidant supplements, which have antiviral effects in the body. These include vitamin C (up to 5,000 mg per day in divided doses), resveratrol (30–200 mg daily), and zinc (10–15 mg daily). But one of the most potent, when it comes to cold and flu prevention, is N-acetylcysteine (NAC), which is a precursor to glutathione, the body’s preeminent antioxidant. A study of older high-risk people showed that taking 600 mg of NAC twice a day for six months resulted in only 25 percent developing flu vs. 79 percent in the placebo group. The researchers wrote, “Administration of N-acetylcysteine during the winter…appears to provide a significant attenuation of influenza and influenza-like episodes, especially in elderly high-risk individuals.”
  • Probiotics are known to enhance immune system function, and studies have shown that these beneficial bacteria may be helpful in preventing colds and other upper respiratory tract infections.
  • Vitamin D is also important, especially during the winter months, because it produces antimicrobial compounds that fight infectious diseases. Take 2,000 IU of vitamin D3 every day, or up to 5,000 IU if your blood levels of this nutrient are low.
  • Beta glucan 1,3/1,6, extracted from cell walls of yeast, keeps the immune system primed and ready to fight off germs. For flu prevention, take 250–750 mg daily.

For the kiddos, gummy vitamins and supplements, like multivitamins, vitamin C and vitamin D can help support immunity. Such chewable supplements can be a double-edged sword due to their sugar content, but if your kids like them as much as candy (as my grandchildren do) you can feel good about these “treats” (in measured doses, of course).

Cold and Flu Treatment

If you do end up catching a cold or the flu despite your best prevention efforts, it’s tempting to run to the doctor to get a prescription antiviral drug or to your local pharmacy to pick up antihistamines, decongestants, pain relievers, and other over-the-counter meds. I get it—cold, and especially flu symptoms, are a total drag. You want to do anything in your power to feel better fast.

The sad reality – as I explain in this article about cold prevention and treatment myths – is that these medications only temporarily ease cold and flu symptoms, and over-the-counter drugs won’t shorten the illness.

Prescription antivirals (Tamiflu and Relenza) aren’t all that effective either. A 2014 review found that at best, these drugs shorten the duration of flu symptoms by half a day. Half a day!! And they don’t appear to reduce risk of pneumonia, sinus infections, hospital admissions, or other complications either. They do, however, have side effects, including nausea/vomiting and headaches—and they are expensive (between $60–100).

Save your money. I know you don’t want to hear it, but if you’re otherwise a healthy person and happen to come down with a cold or the flu, staying home and in bed and sipping on some homemade chicken soup are the best treatments. You might also want to consider giving your immune system a boost by increasing your intake of vitamins D and C while your cold and flu symptoms are at their worst. But really, it will just take patience and time for your body to fight off the viruses.

Dr. Sinatra’s Spicy Chicken Soup

If you are have a chronic condition like cancer, heart disease, or diabetes, or are otherwise at high risk of complications from the flu, be sure to stay in contact with your doctor so that he/she can make sure you don’t need other interventions.


© 2016, 2019, 2020 Stephen Sinatra, MD. All rights reserved.

Leave a Reply


  1. Suzanne Wolinsky

    on January 31, 2018 at 12:30 pm

    Dr. Sinatra ,

    Do you have any suggestions for helping a dry mouth especially at night? Biotene and xylitol don’t seem to help much.

    Thanks! I appreciate your input.

  2. Roger J Carlson

    on February 1, 2018 at 2:34 pm

    I have been using NAC and Vitamin D supplements for a number of years, and they have dramatically reduced the incidence of colds and sinus infections for me. And you can count me among the newly skeptical regarding flu shots. I got sick shortly after getting my flu shot this December. After a day or two, I developed a severe cough and runny nose and lost my voice for over a month. I took Wild Oil of Oregano as a remedy and IMHO it kept me from getting the full blown attack. There was a bug going around at the time and I believe the flu shot temporarily suppressed my immunity, leaving me vulnerable to whatever was going around. I normally don’t get sick from circulating viruses but this time something was different. Normally I get a flu shot during Sept. or Oct. and never had a problem before.

  3. Michael H.

    on March 20, 2018 at 9:10 pm

    I haven’t had a cold or flue since 1998 when I began using my xylitol solution to clean my noes, eyes, ears and teeth. I also take it in my tea. My solution is 5 tablespoons Xylitol in moderately hot water to fill a 250ml spray bootle. I also found out one spray on the eyebrows stops and prevents eyebrow itch for a few months. It is that simple.
    One must be regular. I also have suffered sinusitis since childhood and this has kept it at bay all these years, but I must be consistent. When spraying up the nostrils I bend over so my nose is below my knees to fill all sinus cavities. I am very insistent on being regulate in my practise as breathing easily becomes difficult. One doctor told me I have small nasal passages and suggested a fix too terrifying to contemplate.
    Namaste and care,

  4. Bea Cullum

    on December 19, 2019 at 9:45 pm

    Maybe we do catch cold and flu from not watching our hands , etc but I have not had the flu since 1989, yet I believe cold weather and not having the house heated and always cold is a problem for me. I noticed that since I got married and living in a home that is always cold I had a severe cold last winter 2018 and at this moment that I am write this I am getting over a bad one .(Is that a coincidence?) I have been taken Umcka three times a day since Monday and today is Thursday and my headache , congestion and sneezing have subsided and I only have to get rid of this persistent cough. I always believed that Cold Weather has a lot to do with it . I have always heard from a very young age to cover up good if you go out in the cold because you can get a cold. And that seems to be my case. I do eat my chicken soup and my Vitamin D3 and take Emergency C. I tend to sneeze as night comes along when it is the coldest .So my question is doctor is cold weather also a factor in getting a cold if its always cold in the house. My Friends do not agree with me.
    Thank You so much

  5. Karla Hamlin

    on December 23, 2019 at 9:03 pm

    in a previous article by you, Dr. Sinatra regarding Beta Glucan, you indicated a suggested dose of 10 to 20 mg every other day:
    “So there’s no reason to limit your use of beta glucan to cold and flu season. I recommend 10 mg every other day as a preventive measure, or 10 to 20 mg daily with the onset of symptoms. Take beta glucan on an empty stomach. If symptoms persist, continue dosage for up to three weeks or once symptoms have subsided. ”
    In this article in 2019, you are suggesting, ” Beta glucan 1,3/1,6, extracted from cell walls of yeast, keeps the immune system primed and ready to fight off germs. For flu prevention, take 250–750 mg daily.”
    That seems like a big difference. What amount is best?
    Thank you,

  6. Karen

    on December 26, 2019 at 7:56 pm

    Avoid all vaccines, their risks are not worth their purported benefits. Vitamin D on a regular basis and up you vitamin C intake when you feel any symptoms. Haven’t had a runny nose in years!

  7. HeartMD Editor

    on December 31, 2019 at 2:50 pm

    Hi Karla, Thanks for your comment above – you make a good point. Dr. Sinatra says that there are different varietals of beta-glucan – some are from oats or barley, others are from mushrooms, which can impact dosage recommendations. In a study specifically on beta-glucan for immune support during cold and flu season (at the researchers used 500 mg of beta-glucan derived from Saccharomyces cerevisiae (yeast), and saw positive results (none of the subjects in that test group missed school or work due to colds, while others in the control group did). So 500mg gluco polysaccharide (beta-glucan) is his recommendation for cold and flu prevention.

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