How to Tell the Difference Between a Cold and the Flu (or Swine or H1N1 influenza)

If you’re sneezing, coughing and have a fever, do you know how to tell whether you’ve caught a cold or have the flu? At our clinic, as in clinics and Emergency Rooms all over the world, folks are calling in droves this week to ask if their symptoms might be caused by the Swine Flu (H1N1) virus. So, whether you need to know the answer now or you’re looking into it for future purposes, I can help you sort out this question.

More Information:

The cold and flu are both respiratory illnesses, but they are caused by different types of viruses. 

Flu symptoms usually come on quickly (within 3-6 hours) and consist of a fever, body aches, dry cough, and extreme tiredness. 

Cold symptoms are less severe and people experience a stuffy nose, productive cough, slight tiredness, and limited body aches.

The American Academy of Family Physicians offers this list of cold symptoms, and how to tell them apart from symptoms of the flu:

  • In general, cold symptoms are milder and come on slowly, while symptoms of the flu tend to occur very suddenly.
  • It’s probably a cold if you have a fever no higher than 102 degrees. The flu usually causes fevers higher than that.
  • It’s probably a cold if you have symptoms including a congested or runny nose, sneezing and coughing, watery eyes, and a sore throat.
  • Symptoms of the flu often include nausea, chills, sweats, vomiting, muscle aches, and loss of appetite.

The chart below, adapted from is a quick reference to help you determine if what the symptoms you or a loved one have is more likely to be just a cold — or if it’s the flu. Of course, only your doctor can tell you for sure.

Remember that if you are experiencing flu-like symptoms, it is better to act fast and speak to your doctor within 12 to 24 hours, as the anti-viral medications used to treat the influenza virus must be started no later than 48 hours after the onset of symptoms – and preferably sooner. 

  • SYMPTOM            COLD                                         FLU
  • Fever                    Rare                                            Usually Present
  • Aches                   Slight                                          Usual, often severe
  • Chills                    Uncommon                                Fairly common
  • Tiredness             Mild                                            Moderate to severe
  • Symptoms            Symptoms appear gradually      Symptoms can appear over 3-6 hours
  • Coughing             Hacking, productive cough        Dry, unproductive cough
  • Sneezing              Common                                    Uncommon
  • Stuffy nose          Common                                     Uncommon
  • Sore throat          Common                                     Uncommon
  • Chest Discomfort Mild to moderate                       Often severe
  • Headache             Uncommon                                Common

Also, here’s an on-line tool that can help you differentiate between the flu and a cold – just from your symptoms. 


9 thoughts on “How to Tell the Difference Between a Cold and the Flu (or Swine or H1N1 influenza)

  • Dr. Motley

    Yes but what is the diagnostic difference between the Flu and the Swine or H1N1 influenza?

  • Influenza, commonly referred to as the flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (the influenza viruses), that affects birds and mammals.

    The type A influenza viruses are the most virulent human pathogens among the three influenza types and cause the most severe disease.

    The influenza A virus can be subdivided into different serotypes based on the antibody response to these viruses. The two major categories are the H and N types.

    Some of these types include H1N1 influenza, which caused Spanish flu in 1918, and Swine flu in 2009.

    There are many others, including H2N2, which caused Asian Flu in 1957; H3N2, which caused Hong Kong Flu in 1968; and H5N1, which caused a pandemic threat in the 2007–08 flu season.

    You can learn more about this at

    Dr. Walt

  • Rochelle fr the Philippines

    I’m getting worried as my son is having a cold and slight fever. I’m afraid that he has a flu moreso if it is a(h1n1)! You have answered my question. Now, I can say that what my son has is just a cold. Thanks for the info.

  • Rochelle fr the Philippines

    Dr. Walt, do you suggest I better take him to the doctor for a check-up? Thanks again! Btw, as of the moment there had been no reported case of H1N1 here in our town. I’m really getting nervous. But the symptoms he has seem those of a colds. I’m confused and scared.

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