Why you shouldn't confuse flu with cold

The flu is a serious contagious disease that can lead to complications and even death.
The flu is a serious contagious disease that can lead to complications and even death.

Know the difference between the flu and a cold to protect your loved ones

Knowing the difference between the flu and a cold can help speed up the treatment process and aid a quick recovery.

It will also protect your loved ones from the illness, as timely treatment can avoid complications and prevent the flu from spreading.

Dr Leong Hoe Nam, an infectious disease specialist at Mount Elizabeth Novena Hospital, helps to clear away the confusion that many of us have with flu and cold.

Dr Leong Hoe Nam, infectious disease specialist, Mount Elizabeth Novena Hospital.

What is the difference between flu and cold?

The flu (short for influenza) and cold are two different illnesses caused by different viruses.

Both of them share some similar symptoms, but the flu is more dangerous.

This is because the flu can lead to a wide range of severe complications, including pneumonia, multiple organ failure or death.

On the other hand, the common cold usually does not require any specific treatment beyond taking over-the-counter medications to help ease the symptoms.

In complicated cases, the cold may lead to sinus congestion or ear ache.


How can we tell if we have caught a cold or the flu?

The symptoms of flu are often confused with those of the common cold.

Cold symptoms usually appear gradually. They include:

  • Runny or stuffy nose
  • Sore throat
  • Cough

Unlike a cold, flu symptoms usually come on suddenly. Some people will get most of the symptoms below while others might experience only a few:

  • Fever of 38 to 40°C (although not everyone with the flu will have a fever)
  • Headaches
  • Body aches
  • Chills
  • Weakness and fatigue
  • Diarrhoea or vomiting (more common in children)

Here is a table of comparison of the symptoms:

Symptoms of the flu versus symptoms of a cold. SOURCE: Adapted from CDC at


Why is the flu dangerous?

Many people think that the flu is just a bad cold or a minor illness that does not have any serious consequences.

In reality, the flu is a threat to society and can cause a wide range of severe complications, which can be deadly in some cases. These include:

  • Inflammation of the brain, heart, or muscle
  • Blood poisoning
  • Worsening of existing health problems, such as asthma
  • Pneumonia
  • Multiple organ failure

Globally, the flu affects 5 to 10 per cent of adults and 20 to 30 per cent of children. Global influenza pandemics have led to a staggering number of deaths. For example, the swine flu (H1N1) caused about 200,000 deaths worldwide in 2009.

Singapore typically has two peak flu seasons every year — from May to July, and from November to January. The seasonal flu could be caused by any of these two types of viruses:

  • Influenza A (e.g. H1N1 and H3N2)
  • Influenza B (e.g. Yamagata and Victoria)

In 2017, about 64 per cent of patients with flu-like symptoms in Singapore were tested positive for flu viruses during the peak season.


Are there people with a higher risk of getting complications from the flu?

Flu is highly contagious and can impact people of all ages. But some people have a higher risk of complications from the flu. They include:

  • The elderly (aged 65 and above)
  • Young children (aged below five, especially those aged below two)
  • Pregnant women
  • People with chronic medical conditions (such as heart, respiratory, kidney or liver diseases)
  • People with weakened immune systems (such as HIV infection or those receiving steroids)
  • Residents of nursing homes and other long-term care facilities


How can we protect ourselves and our loved ones from flu?

The flu is a contagious illness that transmits easily from person to person.

The virus spreads mainly by the droplets produced when the patient coughs, sneezes or talks. It can also spread indirectly when a person touches a surface with flu viruses on it and then touches his nose or mouth.

Young children and the elderly are at a higher risk when they come in close contact with someone who has the flu.

Vaccination is an effective way to protect yourself and your loved ones from flu viruses.

If you have the flu, you should avoid infecting others by staying at home and reducing contact with others till you recover. You should also stop the spread of the virus by washing your hands frequently and wearing a mask.

Antiviral flu medications are available to treat the flu. When a viral infection occurs, the virus particles start to replicate and spread within the body. Antiviral medications treat the flu by reducing the virus’s ability to do this.

This can help to shorten the length of the illness, lessen the severity of symptoms, and avoid complications from the flu.


When should we consult a doctor?

The earlier you seek treatment, the better. If you feel ill with some or all of the flu symptoms listed above, speak to your doctor early, preferably within 48 hours, to confirm a diagnosis.

Early diagnosis and treatment can protect you from the flu and its complications. Your doctor may prescribe treatments such as antiviral flu medications, which can help you feel better sooner than if you didn’t take one.

It’s also important to note that because the flu is caused by a virus and not bacteria, antibiotics cannot target the source of the flu and will not help you get better.

So if you suspect you have the flu, remember that antibiotics will not have any effect, and see your doctor as soon as possible.

To learn more about the flu, head to

This article is brought to you by Roche.