Covid-19 vs a Cold

Do I have a simple cold, allergies, flu or Covid-19? With many overlapping worrying symptoms, it can be hard to know what illness you may have. Here’s how to tell the difference.

We advise all our patients with any cold/flu/allergy symptoms to have a COVID test.

Fever, chills, body aches and cough can be common symptoms with many viruses and it can be difficult to differentiate between a cold, the flu and COVID19. Symptoms described above create alarm for many of us during the current pandemic.

But the good news is that the above illnesses respond in the majority of people to usual measures such as fever control, plenty of fluids and supporting the immune system with a nourishing diet and rest.

How do we know the differences between a cold, the flu, COVID-19 and allergies? 

Symptoms of a cold

A simple cold usually produces milder symptoms including the following:

  • Runny or stuffy nose, sneezing, watery eyes
  • Cough (mild)
  • Fatigue (sometimes)
  • Sore throat
  • Headaches (rarely)
  • Aches and pains

Shortness of breath is NOT a symptom.  Fluids and over the counter medication help with symptoms but one’s innate immunity works to resolve the symptoms over 7 – 10 days. There is no long lasting immunity after a cold and re-infection can occur. 

Symptoms of Flu/ Influenza

The flu is caused by the influenza virus. This also affects the nose, throat and respiratory system but comes on very suddenly and can last from 5 to 7 days. Here are some common symptoms of the flu:

  • Fever – usually high and/or chills
  • Cough (usually dry)
  • Fatigue
  • Aches and pains
  • Runny or stuffy nose, sore throat
  • Vomiting and diarrhea especially in children

There is no active treatment required for influenza. One should stay at home and manage symptoms of fever with paracetamol/ ibuprofen, adequate rest, fluids and an immune boosting diet.  Antivirals are available but these are rarely needed. There is no need to take antibiotics as this is a viral illness.

If the illness appears to be lasting longer than a week and the symptoms such as fever and cough get worse after getting better, this may signal a bacterial infection setting in and it is best to see a doctor.

Symptoms of Coronavirus or COVID-19

The coronavirus family has been known to cause common colds for many years. However the particular strain that has caused the pandemic 2020 – novel coronavirus or SARS-CoV2 is potentially deadly and causes COVID19. This strain was not previously known to occur in humans. It can vary from being a mild or symptomless illness in young healthy people or children but a serious illness in certain groups. The elderly, those with heart disease, lung disease, and diabetes as well as others with compromised immunity appear to be at a higher risk.

Symptoms of COVID-19 can start 2 days after infection and last up to 2 weeks. There can be long-standing fatigue afterwards. Symptoms include:

  • Fever and/or chills
  • Cough (usually dry)
  • Shortness of breath or difficulty breathing
  • Tiredness
  • Aches and pains, headaches, sore throat
  • Loss of taste and smell
  • Vomiting and diarrhea
  • Unusual sudden cardiac events and clots in deep veins have occurred due to the inflammation produced in the circulatory system.
  • Blisters/ rashes and wheals have all been reported recently with a small number of COVID19 infections.

There’s currently no cure for the disease although some drugs have been tried to reduce the severity and duration of illness in those that are hospitalized.

How can you tell the differences between the flu and COVID-19: COVID-19 symptoms that are not seen in influenza include a loss or change in taste and smell, skin reactions and difficulty breathing. Unfortunately, fatigue can ensue for many weeks or months and the disease is still being studied due to heart attacks, clots in the legs or lungs and blood vessels noted to be occurring even after apparent recovery.

When do I need to see a doctor?

Influenza does not usually require a test although a swab may be available in some clinics. Unfortunately, a co-infection with COVID19 is possible and a nasal/ throat swab can be performed to differentiate between the two.

It is important that people report symptoms as soon as they occur and this is contrary to the advice offered in the past, which was to manage the symptoms with rest, over the counter medication, and fluids for the first few days of a viral illness. Early testing means that infected people can be isolated, contacts traced quickly, and disease spread curtailed.

IMC offers consultations for adults and children alike for the above illnesses. There is a systematic workflow to organize swabs and prompt follow up of our patients. Flu vaccines are also made available to patients depending on the season.

Can I prevent these diseases and is there a treatment available?

  • Prevention remains paramount. It is important to practice hand hygiene and protect oneself from air droplets that are released by infected people, even before they develop symptoms. At this time of uncertainty with influenza viruses and COVID19 circulating, using a mask, avoiding sharing cups/ plates and wiping down surfaces that could harbour these viruses are routine recommended measures.
  • Unlike for colds, vaccination can prevent influenza. The disease can be caused by different strains and the seasonal flu vaccine is released twice a year. If one does develop the disease despite the vaccination, it is likely to be milder. Hence the vaccine is recommended especially at the current time when we expect a ‘twindemic’ of COVID19 and influenza to occur in the coming months and to prevent some serious complications of the disease.
  • There is a strong recommendation for certain groups of people with lower immunity such as those younger than 5 years (especially those under 2 years), over 65 years, those with asthma, cardiac conditions and pregnancy to have the flu vaccine during the flu season.
  • Hygiene precautions, physical distancing and isolation remain the cornerstone of managing spread of COVID19 till a cure or reliable COVID19 vaccine become available.
  • The pneumonia vaccine against bacterial pneumonia should be offered to high risk groups and the elderly. Again, this will not protect against the above viral illnesses but reduce the risk of bacterial complications.
  • The immune system can be boosted with a healthy diet rich in Vitamin C, anti-oxidants and adequate Vitamin D levels should be maintained. Zinc supplements have helped in some studies. Adequate sleep can also ensure optimal immunity.

The table below allows for easy comparison between symptoms in these illnesses:


Signs + Symptoms Cold Influenza (Flu) Covid-19
Symptom onset


Gradual Abrupt Sudden
Fever Rare Usual; lasts 3-4 days Often
Aches Slight Usual; often severe Sometimes
Fatigue, weakness Sometimes Usual Usual
Chest discomfort, cough Mild to moderate; hacking cough Common; dry Often, dry
Stuffy nose Common Sometimes Rare
Sore throat Common Sometimes Sometimes
Headache Rare Common Sometimes
Loss of taste/ smell        


Rare Rare Common


Rare Sometimes Rare
Shortness of breath


Rare Rare Often

Could this just be my allergies coming back?

Yes it can cause confusion – look for the following that favour an allergy more than a virus:

  • Itchy nose, eyes, throat, sinuses, and ear canals
  • Fatigue (sometimes)
  • Cough
  • Sneezing
  • Runny or stuffy nose
  • Watery eyes
  • Headaches (sometimes)
  • Shortness of breath/ asthma like reaction to the triggering substance.

Fever is not a feature. The most common cause of allergies is triggered by environmental allergens such as pollen, dust, mould, pet hair etc.  The immune system triggers antibody production and histamine which causes itchy eyes, nose etc. Avoidance or the allergen and over the counter medications such as antihistamines and decongestants can help. A doctor can prescribe a steroid nasal spray or eye drops.

If you’d like to know more or talk to a doctor about symptoms please get in contact with us.


Dr Charu Narayanan is a UK trained GP based at IMC Katong. Call 6342 4440 to make an appointment with Dr Charu.


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