Despite having similar symptoms, these winter respiratory diseases can have VERY different results.

Cold and Flu and some of the most commonly misused words in medical science. Blocked sinuses and a stuffed nose are almost always dismissed as “just a cold”, and we carry on our everyday lives, hoping that the symptoms will run their course and promptly leave.

However, it is time to think about this course of action in a bit more detail. Around 200,000 people in the U.S. are hospitalized for Influenza each year; around 36,000 of whom die due to the virus.

As the symptoms of the common cold and the potentially-deadly flu virus appear to be very similar, this report will aim to educate you on how to tell the difference and keep yourself safe.

The Common Cold: What is it?

The common cold is an upper respiratory tract infection. The infection is caused by a variety of viruses, but the infection is almost always mild in nature. The common cold is transmitted from person to person by droplets produced during cough and sneezes, or through direct contact with a contaminated surface. Contrary to what many have come to believe, being in the cold weather does not actually cause the common cold.

The Science

More than 200 different varieties of virus are known to cause the common cold; the most common of these being rhinovirus (this causes around30-40% of colds in adults). 

Due to the fact that numerous different viruses cause the common cold, and because these viruses are constantly mutating to develop new strains, the body is not able to build immune defenses directed towards the illness. This is why you have many colds throughout your life time: you simply don’t develop immunity.

Young children experience on average 6 to 12 colds per year. While the cold has no direct relation to causing the common cold, it does occur more frequently during the colder months.

Who is at risk

There are variety of risk factors that come into play when it comes to determining how likely an individual is to acquire the common cold.


Infants and young children have not yet developed immunity to many common viruses, and therefore are at increased risk of developing the common cold. Adults will have developed limited immunity to some strains of the common cold so become ill less often. The elderly population also has an increased risk of developing the common cold as their immune system deteriorates with age.

Seasonal Variation:

The common cold is acquired more in a much larger proportion of the population during fall, winter, or during the rainy season. As the illness is not directly related to the weather, it is thought that in increased prevalence at these times is most likely due to people spending more time indoors and in closer proximity to each other. 

Weakened Immune System:

Those who have poorly functioning, weaken immune systems have an increased likelihood of developing the common cold. This includes individuals with excessive fatigue, emotional distress and disorders of the immune system.



It is likely that a cold will develop gradually over a series of two or three days. Individuals are most contagious during the early stages. This is the duration in which symptoms are likely to include a runny nose and sore throat.

Symptoms of the common cold include:

  • Blocked or runny nose
  • Sore throat
  • Headaches
  • Cough
  • Sneezing
  • Pressure in the ears and face (blocked sinuses)
  • Loss of taste and/or smell
  • A high temperature or fever
  • Muscle aches and pains
  • Feeling exhausted and need to lie down

Nasal symptoms are experienced more frequently during infection with the common cold than with influenza. The nose will normally produce a watery secretion for the first few days, that will later thicken and become darker in color.

Infants and young children may also become fussy and have decreased appetite.

How long does it last?

The duration of colds can vary, but colds to tend to last for longer than flu. Individuals who are still ill after a duration of two weeks or longer most likely have a cold; although a cold could also last as little as two days.

How Serious is the Common Cold? How Should I Treat it?

Generally, a cold is nothing to be worried about. In vulnerable populations, such as infants and the elderly, a suspected cold should be monitored more closely in case of symptom development and further complication. 

The common cold should be treated at home, and the is normally no reason to contact a doctor. Keeping warm, getting rest and sleep and drinking plenty of water with aid in a speedier recovery. Pharmacists can help you, selling cough and cold medicines over the counter. A pharmacist will be able to advise you on the best medicine for you needs.

Nasal sprays are available to relieve congestion and aches, pains and temperature can be lowered with pain killers such as paracetamol or ibuprofen. Some medications are not suitable for children, babies or pregnant women, so make sure to specify who the medicine is for if you are buying in for someone else.

Supplements such as vitamin c, zinc, Echinacea and garlic also lay claims to help in your recovery, but there is little evidence to support their supposed effects.

The Flu: What is it?

Influenza, commonly known as ‘The Flu’, is a contagious respiratory illness caused by influenza viruses. These infect the nose, throat and lungs. The flu viruses are believed to be spread via airborne droplets produced when infected individuals cough, sneeze or talk. The virus may also be transmitted through touching a surface that is contaminated with the virus, then touching one’s own mouth, nose, or possibly eyes. Influenza is a more serious illness than the common cold, and there is a potential that medical attention may be needed. Complications of the flu can include bacterial pneumonia, ear infection, sinus infection, and the worsening or chronic conditions such as heart failure, asthmas or diabetes.

The Science

Influenza viruses can be unpredictable but are likely to be moderately severe even if the infected individual is healthy to begin with. However, for those who are unhealthy to begin with, the infection has the potential to be fatal.

The virology of Influenza is an interesting topic. The Influenza viruses are a group of RNA viruses that have a very high rate of mutation. The mutation rate of the virus is caused by rapid change in viral genetics produced by antigenic drifts. ‘Antigenic drift’ is a sudden large change in the virus genetics which allows the virus to infect a new host species quickly and overcome protective immunity any individual host might have developed to the virus previously.

This is big reason behind the semi-frequent emergence of flu pandemics. These strains are often of animal origin, such as bird flu or swine flu.

Who is at risk

The risk factors that predispose individuals to an infection of the Flu Virus are the same as those that increase the risk of contracting the Common Cold (age, seasonal variation, weakened immune system). 

The major difference here is that for those individuals who fall into the ‘high-risk’ group, influenza can become severe and even fatal. This group includes those who suffer from:

  • Asthma
  • Emphysema
  • Chronic Bronchitis
  • Bronchiectasis
  • Tuberculosis
  • Cystic Fibrosis
  • Heart Disease
  • Chronic Kidney Disease
  • Chronic Metabolic Disorder (e.g. Diabetes)
  • Anemics

Individuals who are:

  • Immunocompromised (due to disease or medical treatment such as chemotherapy)
  • Senior Citizens (especially those residing in health care facilities)
  • Pregnant
  • Infants and Young Children

Those who fall into any of these categories are offered the Flu Vaccine on an annual basis; more on this later.


Flu symptoms use usually more severe than cold symptom and are likely to come on much more rapidly - within the duration of a day, or even a few hours. Symptoms will begin approximately 2 to 3 days after the infection originally occurred.

Influenza symptoms are very similar to that of the Common Cold, though some of the symptom typically present themselves to a greater or lesser extent. Symptoms that are more likely to be worse in the case of a Flu infection are:

  • High Temperature
  • Feeling Exhausted
  • Muscle aches and pains
  • Headaches
  • Sinus Pain

How long does it last?

Cases of Influenza tend to be more predictable in their length than cases of the Common Cold. The Flu will normally last for the duration of about a week, though you are likely to feel tired or ‘out of sorts’ for much longer.

How Serious is the Flu? How Should I Treat It?

As you have gathered by this point in the report, the Flu is a much more serious viral infection than the Common Cold.

In general, the Flu can still be treated at home without medical attention. People with the flu are advised to take plenty of rest and drink plenty of fluids to avoid dehydration. Alcohol and Tobacco use should also be avoided (as always). If necessary, pain killers can be taken to relieve the headaches and muscle pains associated with the flu.

Antiviral medication may be effective if they are given early enough - but some strains of influenza are beginning to show resistance to several of the standard antiviral drugs, another issue presented by the virus’ mutation rate.

Once again, suggested supplements and holistic/ herbal therapies that are often advertised for Cold and Flu have little evidence behind then to suggest they are effective in 
treatment of these infections.

An Aside: 10 Misconceptions about Cold and Flu

1. The flu vaccine causes flu
the viruses contained in flu shots have been killed, so they cannot cause infection
2. You can catch a cold from getting cold
the reason cold and flu are more common in the winter months is more likely to be due to people spending more time indoors, and therefore being at closer proximity to each other.
3. You should avoid dairy if you are sick
dairy does not cause your body to make more phlegm and it can actually be soothing on sore throats and provide calories that might not otherwise be consumed during illness
4. Your cold could turn into the flu
The common cold and influenza are cause by different viruses; there is no way a cold can ‘morph’ into the flu
5. The flu isn’t that serious
Most cases will not require medical attention, but the flu should always be closely monitored as complications from the flu can be deadly
6. Staying away from sick people is the only way to stay well
This is not a foolproof method of prevention and the flu vaccine should always be opted for when it is available
7. If you hate shots, you can get the nasal spray instead
The nasal mist flu vaccine is only licensed by the FDA for use in healthy people aged 2 to 49. Individuals who fall outside of this category, will be required to have the shot
8. If you don’t get a flu shot by January, it’s too late
Flu season often peaks in February, so it is never too late to get vaccinated
9. Getting vaccinated every year isn’t necessary
The flu virus does change year-on-year, so it is crucial to stay up to date with annual vaccination programs.
10. Flu medication will help to clear up a cold too
Flu antivirals only work against flu viruses and will not help reduce symptoms of the common cold to other flu-like illnesses.

When do I call a doctor for cold and flu symptoms?

In most cases or cold AND Flu, there will be no need to contact medical professionals. Treatment can be performed at home as is previously described.

The fact that cold and flu are both viral infections should be kept in mind. Doctors cannot prescribe medication to treat either effectively, and antibiotics will have no effect. If symptoms appear to be unusually serve or the effected individual falls into a high-risk group, a GP should be contacted. Look out for these symptoms in particular:

Persistent fever:

If your fever lasts for more than three days, it is possible you also have another bacterial infection, secondary to the cold or flu virus, that needs to be treated.

Painful swallowing

Sore throats can cause mild discomfort in a normal case of cold of flu, but severe pain could be indicative of ‘Strep Throat’, an infection that will require treatment by a doctor.

Persistent coughing

A cough that does not subside, at least slightly, after three to four days could in fact be bronchitis. Antibiotics will be needed to treat this inflammatory condition.

Persistent congestion and headaches

Congestion and blockages of the sinus passages can cause sinus infection (sinusitis). If pain around the eyes and face is felt persistently, with accompanying thick nasal discharge, a bacterial infection might be present. There is a possibility that antibiotics will be required to treat this, but this is unlikely.

Emergency medical attention should be sought immediately in some cases, signs of crisis include:

  • Severe chest pain
  • Severe headache
  • Shortness of breath
  • Dizziness
  • Confusion
  • Persistent vomiting

Additional signs of emergency exhibited by children are:

  • Difficulty breathing or rapid breathing
  • Blush skin color
  • Not drinking enough fluids
  • Lethargy and failure to interact normally
  • Extreme irritability or distress
  • Symptoms that were improving, suddenly worsen
  • Fever with a rash

How do I prevent cold and flu?

Public Health Measures

Measures that can be put in place to avoid both cold and flu are very similar. The best preventative actions include: hand-washing, not sharing communal kitchen wares (like cups and cutlery), and avoiding direct contact with individuals who appear ill.

The viruses are both transferred between hosts via airborne droplets or other respiratory secretion, therefore it is important that mouths should be covered, and tissues used when coughing or sneezing in public. Tissues should then be properly disposed of and hands thoroughly washed to prevent infection spread.

Possibly contaminated surfaces (e.g. tables in restaurants, door handles in the office) should be cleaned routinely with virus-killing disinfectant.

Individuals have the potential to transmit the infection for as long as they have a fever. 24 hours after a fever has fully subsided is when an individual no longer presents as infectious. If suspected to be sick, individuals should take it upon themselves to abstain from being in crowded public spaces.

Social distancing is a more extreme strategy used during pandemics. This involves closure of schools, churches and theatres, workplaces, and many other public facilities. The spread of the virus is slowed considerable through taking this action due to minimized social gatherings. In past cases, social distancing has had no measurable impact of the reduction of the overall death rate from flu, however.

Ensuring maintenance of a healthy immune system is also important in avoidance of cold and flu. This involved general maintenance of health and well-being through diet and exercise. Stress can also impact on immune system health.

The Flu Vaccine

Vaccination against the Influenza Virus is recommended by the World Health Organization (WHO) and the United Stated Centers for Disease Control and Prevention (the CDC). The CDC recommends that ‘everyone’ be vaccinated. Vulnerable groups such as children, pregnant women, and people aged 50 and over should take priority when it comes to vaccination programs.

Unless there is a contraindication present, there is no reason to not get the Flu vaccine. Unfortunately, one common contraindication is egg allergy, as the vaccine is synthesized from chickens' eggs. Other contraindications would be having received a different vaccine within the two weeks previous or being ill at the time of your scheduled vaccination.

Flu has a high mutation rate therefore the flu vaccination doesn’t work like most other vaccinations. When you are vaccinated against small pox, for example, you are provided with life-long immunity. A Flu vaccine however, will usually confer protection for no more than a few years.

As Flu reaches its peak prevalence in winter, every year there are two different flu seasons, due to our earth being divided into the Northern and Southern Hemispheres. The WHO (World Health Organization) makes recommendations for two different influenza vaccines every year; one for each hemisphere. Predicting the strains of flu that will likely be present in each hemisphere, each year requires large volumes of time consuming research performed by National Influenza Centers.

It takes pharmaceutical companies and their manufacturers around six months to produce the millions of doses needed for the population; occasionally, a new or overlooked strain will have become prominent during that time, rendering the new vaccination redundant.

Final Words

Having read and digested this information, you should now feel better equipped to tell the difference between the Common Cold and an Influenza infection.

Knowing the symptoms, basic treatment and preventative measures will all play a role in keeping you healthy this flu season.

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