symptoms: is it a cold, the flu, allergies, or coronavirus

If you have symptoms: is it a cold, the flu, allergies, or coronavirus?

Infectious Disease,

All of us are on alert now for coronavirus, but do not panic. Most illnesses with respiratory symptoms are not caused by the new coronavirus.  Such symptoms more likely are due to common flu, a cold, or allergies. But it may be difficult to differentiate between the various diagnoses, especially when the symptoms are beginning. 

However, there are certain characteristics of each of these that can help us decide if our symptoms are something more ordinary, like the flu, or more serious. Making a diagnosis, without lab testing, is like being a detective. You consider all the symptoms, and how they are progressing or improving, and you can get a good idea of the diagnosis.

Regarding definitions: the new coronavirus is technically referred to as SARS-CoV-2 and the disease caused by this virus is called COVID-19.

If you develop symptoms, here are some general characteristics that will help you decide if you should be concerned. A definitive diagnosis of COVID-19 requires a swab taken from the nose or throat. The results may be available in a few hours, but it might take time for your specimen to be sent to the appropriate lab for testing.

Coronavirus Symptoms

  • The typical symptoms are fever and dry cough
  • May start 2 to 14 days after exposure, but the average time from exposure to symptoms is 5 days
  • Fever, noted by up to 90% of patients, is often the first symptom, and may be high (above 39º C.)
  • Dry cough may be associated with shortness of breath or chest tightness, which indicate a more severe infection
  • A feeling the whole body is affected, often with muscle and joint aches and pains (also typical of common flu)
  • Often with a history of travel to an affected area, or known exposure to someone with COVID-19, or living in an area where there is already community spread of the infection
  • Symptoms may get worse over the first week 

The Common Flu

  • Usually symptoms begin 1 to 4 days after exposure
  • Comes on suddenly, with more pronounced tiredness, and whole-body aches and pains (compared to COVID-19)
  • May affect nose (stuffy or runny nose)
  • Headache common
  • Fever and cough common
  • Rarely gives breathing problems
  • Typically starts to improve after a few days with proper care

The Common Cold

  • Usually develops slowly over a few days
  • Fever usually not present
  • Nasal symptoms and sore throat most common
  • Headache and cough less common


  • No fever
  • Itchy eyes; stuffy, runny nose, with sneezing common 
  • Should not make you feel sick throughout your body; symptoms typically all in head area
  • Gets better with antihistamine pills 

When to seek medical help

If you think you have allergies or a common cold, you probably don’t need to see a doctor. But, on the other end of the spectrum:  if you have problems breathing, or can’t get enough air into your lungs, you need medical help right away.

Differentiating the common flu from COVID-19 gives the most difficulty in diagnosis. If you are concerned with the severity of your symptoms or are getting worse, call your doctor or go to a medical center!

To find a doctor, of any specialty, anywhere in Brazil, check out our website:

See also in ProcuraMed:

How to boost your immunity in the age of coronavirus

Four ways to avoid the coronavirus

Esta postagem também está disponível em: Portuguese (Brazil)

Recommended doctors

This post is related to specialty Infectious Disease. Below is a list of some physicians related to this specialty.