Loss of Smell May Suggest Milder COVID-19

Coronavirus disease (COVID-19) is a contagious infection caused by a virus known as the Corona, rapidly spreading all over the world declared by the WHO as a pandemic. The virus spread from an infected person to a healthy person utilizing aerosols and airborne and surface transmission.

An infected person often exhibits, loss of smell, a situation where a person loses the ability to sense smell. There are different reasons for loss of smell like

  • Common cold and flu
  • Sinusitis
  • Allergies
  • Due to medication side effects
  • Smoking
  • Milder COVID-19
  • Old age
  • Underactive thyroids
  • Alzheimer’s disease, etc.

As mentioned above, there are different causes for losing the sense of smell. There may be a chance of suffering from COVID-19 too. In a study, it concludes that the loss of sense of smell, also known as anosmia, is a feature to confirm COVID-19. The sense of smell is due to the Olfactory sensory neurons present in the tissues high inside the nose, responsible for the ability of smell.

These olfactory sensory neurons connect directly to the brain. Angiotensin-converting enzyme 2(ACE2) is an enzyme attached to the cell membrane of the cell lungs, arteries, heart, kidney, and intestine. A research study is identified and stated that this ACE2 is somewhat supporting these coronaviruses to enter the body.

The olfactory sensory neuron doesn’t contain these ACE2 but the supporting cells of aroma molecule receptors. The virus clings on to the outer surface of the cell with ACE2. Thus the coronavirus alters and affects the process of transmitting the signals regarding smell to the brain, leading to loss of sense of taste and smell. The protein belong to the serine protease family called transmembrane protease serine 2(TMPRSS2) helps the coronavirus further to occupy the cell.

This COVID-19 has mainly three stages

  • Stage 1: the initial stage of infection where mild symptom occurs in the human body. In this phase, the virus starts reproduction through the viral replication process and increases its number in the body. The condition may refer as milder COVID-19. In this stage, many symptoms appear, which may confuse some time, whether it is COVID or other diseases. Symptoms like fever, muscle pain, sore throat, breathing difficulties, headache, loss of sense of taste, loss of sense of smell, diarrhea, tiredness, dry cough, fatigue, etc. Some time symptoms might change from person to person.
  • Stage 2: it is a pulmonary phase where it affects the respiratory system and causes symptoms like continuous cough, insufficient oxygen levels, breathing shortness problems. And the immunity system gets severely affected.
  • Stage 3: this is the hyperinflammatory phase. In this, the immune system gets hyperactivated and attaches its body tissues, leads to damage to the lungs, heart, and other organs in the body.


Nowadays, many people are suffering from COVID-19 and also died. Some people are confused about whether the virus has infected their health. Loss of smell is one of the symptoms of milder COVID -19 when the virus enters through the nose. But the alone loss of sense of smell or changes in the sense of smell cannot determine milder COVID because the virus can enter through the mouth also.