Difference Between Coronavirus vs Flu vs Cold vs Allergies

Coronavirus refers to covid-19 which is a new virus that causes respiratory issues. Several strains of the influenza virus can cause respiratory problems. The common cold can be caused by a wide variety of viruses, and it often only lasts a few days. Allergies are caused by environmental allergens.

What is Coronavirus?

Coronavirus, also known as COVID-19, is a pandemic in which a virus is causing respiratory sickness and killing more people than the typical seasonal flu.

  • Genetics and origin of the coronavirus − The covid-19 coronavirus seems to have emerged originally in China, where it spread from an animal to a person. The specific host animal from which the virus originated is still up for contention. It has been discovered to be comparable to the SARS coronavirus, a single-stranded RNA virus with glycoproteins on its outer surface.

  • Symptoms and complications − A high temperature and a dry cough are the most noticeable and noticeable signs of covid-19 infection. However, the infection can cause serious lung damage in some patients, which can make breathing extremely difficult. This results in a lack of oxygen in the blood, which can lead to cardiac issues or failure of numerous organs. Age and health factors affect death rates, yet even young, seemingly healthy people might pass away.

  • Diagnosis − A human sample can be tested using RT-PCR. Some nations now offer drive- through testing locations where anyone may pull up and have a sample taken for testing. The test is effective because it confirms a diagnosis by checking for the virus's unique genetic coding.

  • Transmission − It is believed that the coronavirus known as covid-19 is a zoonosis that was accidentally spread from an animal host to people. Human to human transmission then happened.

  • Risk factors and mortality − Mixing with infected people increases your risk, although you won't notice any signs for a time. While treating patients with covid-19, medical personnel are likewise at danger. Because of this, several nations have adopted policies of social isolation in an effort to lessen interpersonal contact. The largest fatalities occur amongst those older than 70 years and who have other ailments. Diabetes and heart disease appear to enhance the risk of covid-19 problems and mortality.

  • Treatment − Pain relievers are used to manage the symptoms, and the patient may also require fluids to help with the dehydration brought on by the fever, as well as supplementary oxygen for any breathing issues. In really severe circumstances the person may need to be on a ventilator to support breathing.

What is Flu?

Seasonal influenza is a contagious viral disease that often affects the upper and lower respiratory systems

  • Symptoms and how it spreads − Body aches and pains, a headache, a cough, a fever, a sore throat, and a stuffy nose are all signs of the flu. Those who are ill can readily spread the flu to others since it is infectious.

  • Mortality − The fatality rate from the flu is roughly 1/10th that of the covid-19 yet it does cause many individuals to die every year, particularly the very young and extremely old. Mortality, though, can vary depending on the type of flu.

  • Treatment − Therapy is mainly symptomatic although antibiotics may be given if a subsequent bacterial infection is suspected.

What is Cold?

A cold is a viral sickness that affects the upper respiratory system and causes a mild illness that generally goes away on its own.

  • Symptoms and how it spreads − A sore throat, cough, and congestion in the nose and sinuses are all signs of a cold. Although colds often do not cause fever, they are very infectious and spread quickly from person to person.

  • Mortality − Individuals do not normally die from a cold unless they have an exceedingly weak immune system, such is the situation with persons who have HIV.

  • Treatment and diagnosis − A cold is generally diagnosed on the basis of the symptoms and the lack of a temperature or chest difficulties.

What are Allergies?

An allergy is a response to some allergen in the environment such as pollen, ragweed, or smoke

  • Symptoms and how it spreads − Red, watery, and itchy eyes, a runny nose, sneezing, and occasionally a rash are all symptoms of allergies. Allergies are not communicable and hence there is no danger of making others sick.

  • Mortality − Few people die from allergies, but those who do can have a potentially fatal episode of anaphylaxis if they are prepared with an EpiPen, receive prompt medical attention, and prevent exposure to the allergen.

  • Treatment and diagnosis − A person can be identified through various allergy testing and antihistamines can assist with symptoms. Due to the risk of anaphylaxis, it is advisable to avoid harmful allergies.

Differences: Coronavirus vs Flu vs Cold vs Allergies

The following table highlights the major differences among Coronavirus, Flu, Cold, and Allergies −







Coronavirus is an infection of the lower respiratory system caused by covid-19.

The flu is an infection due to the flu virus.

A cold is caused by many different viruses.

Allergies are a response of the immune system to an allergen.

Causative agent or agents

Coronavirus is caused by a type of betacoronavirus

The flu is caused by the influenza virus in the family Orthomyxoviridae

A cold is caused by many viruses, but most often, rhinovirus.

Allergies are caused by environmental allergens.

How soon symptoms appear

The symptoms of covid-19 show up from 2 to 14 days after infection.

Flu symptoms appear from 2 to 7 days post- infection.

Cold symptoms appear in about 1 to 3 days.

Allergy symptoms usually show up immediately or within a few hours of exposure.

Most common symptoms

Coronavirus has symptoms of high fever, dry cough and problems with breathing.

The flu symptoms include fever, body aches, sore throat, a cough, a congested or runny nose.

A cold has symptoms of sore throat, congested nose, a cough, but no fever.

Allergy symptoms include red, itchy water eyes, and congested or runny nose, and sometimes a rash.

Level of contagiousne ss

The coronavirus is very contagious,

The flu is also contagious conditions but not as contagious as covid-19.

The cold is also contagious conditions but not as contagious as covid-19.

An allergy is not a contagious condition.


While coronavirus, flu, cold, and allergies all cause respiratory symptoms, they are caused by different agents and have different modes of transmission and severity of symptoms. Understanding the differences between these illnesses is important for seeking the appropriate treatment and preventing the spread of illness.

If you have symptoms of a respiratory illness, it is important to seek medical attention to determine the cause and receive appropriate treatment.

Updated on: 17-Apr-2023


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