COVID-19 Risk Factors

What is COVID-19?

Coronavirus disease (COVID-19) is an infectious disease caused by the SARS-CoV-2 virus, one of the viruses from the corona family which causes respiratory problems in humans.1 Initial cases of COVID-19 were reported in Wuhan, China in December 2019, where this new strain of coronaviruses was found. This disease then spread throughout the world.

COVID-19 is considered a highly transmissible disease as one infected person, when coming into contact, can transmit the germs to typically three other people around them.2

Symptoms of COVID-19

Every individual has a different level of severity according to the symptoms. Elderly population and those with underlying diseases may have serious symptoms and complications.3 General indications of COVID-19 are as follows:

  1. High-graded fever.
  2. Cold and cough
  3. Muscle and body weakness
  4. Headaches. 

In a study based in England, around 1 million COVID patients, showed seven similar symptoms which were loss of senses (taste and smell), fever, cold, new onset of cough, loss of hunger, and muscle pain.4

Who is at risk of infection?

COVID-19 is a global pandemic, hence it is harmful to every individual who comes in contact with the virus. However, certain people have a higher possibility of getting infected. Individuals having  close contact with infected people, traveling to and from the areas where the disease is widely spread, and are above the age of 60 with already existing health conditions possess a higher risk of catching the infection.3

What puts you at risk of more severe COVID-19 symptoms?

Let’s discuss some of the risk factors for severe COVID-19 symptoms:

Chronic health conditions

As we know Coronavirus primarily affects our respiratory tract and lungs, pre-diagnosed respiratory illnesses can increase the risk of complications. Other diseases which deteriorate body's ability to fight against infections are also leading causes of aggravated symptoms.

A study based on 17 million people reported that individuals at greater risk of COVID related deaths were mostly patients with diabetes, heart problems, persistent respiratory conditions (Asthma), different types of cancers, kidney and liver problems, and other immunity problems.5


It is very well known by the facts that people with diabetes are at elevated risk of infections because of their low immune response,6 as diabetes can escalate inflammation in the body consequently weakening the immune system, and making it tougher for individuals to fight off the virus. 

Uncontrolled blood sugar levels are another important risk factor for viral infections. Excess glucose in the blood prepares an environment for viruses to grow and multiply, eventually leading to severe symptoms and complications.7

Respiratory health problems

As explained earlier, the entry portal for coronavirus is the respiratory tract hence pre-existing airway or lung diseases can become a platform for the virus to thrive. This can be because of inflammation or damage to the tract. Some of these conditions include COPD, Asthma, Tuberculosis, Pulmonary diseases, etc.7

Individuals with existing respiratory diseases and COVID are at greater risk of developing severe complications and have higher death rates as compared to infleunza patients and those with no underlying lung problems.8

Cardiovascular problems

Impaired respiratory function because of coronavirus can burden pumping organ of the body. The workload of the heart will simultaneously increase when the lungs are overloaded and this will be a challenge for those who are already surviving cardiovascular problems.7 This burden on vital organs of the body will eventually increase the requirement for oxygen, ventilatory assistance and therefore will lead to more complications and deaths.9

Being immunosuppressed

Immunocompromised is a term used for individuals with a weakened immune system that puts them a risk of easily acquiring infections and developing bad symptoms in the body. 

Due to the impaired defense mechanism, both because of certain underlying conditions and certain treatments, individuals may experience aggravated signs and symptoms.10 There are various conditions in which our immune system is damaged, for example, due to some innate conditions (autoimmune diseases), long-term use of steroids, organ transplants, and some kinds of cancers and their treatments.7

Undergoing chemotherapy

Chemotherapy is a treatment undertaken by cancer patients. Since people who are diagnosed with cancers can develop illness because of their exhausted immune system, chemo medicines further worsen their bodies, making them more prone to get infected by contagious diseases like COVID-19.7

Recent organ transplant

Recipients of solid organ transplants (SOT) usually have certain comorbidities like older age, diabetes, high blood pressure, lung diseases, and other heart and immunity disorders. These health conditions make individuals liable to the risks of severe COVID-19 infection. Another risk factor for SOT receivers is the intake of immunosuppressive medicines, as this therapy can raise their vulnerability to the SARS-CoV-2 virus.11

Being unvaccinated

Like other vaccines, the COVID-19 vaccines also provides extra protection against the viral disease. Unvaccinated people have higher chances of ending up in hospitals because of poor immunity. A study reported 64% increase in immunity after getting first dose of vaccine which rises to 94% after second dose. Thus, vaccination is considered important against COVID infection.12

It is highly recommended to take initial doses as well as boosters of COVID-19 vaccines to prevent complications and stay protected.13


Many researchers found that the risk of COVID-19-related deaths is higher in the elderly population because of their underlying health conditions which make them vulnerable to the infection. While some studies identified this risk regardless of health conditions 14 since aging can affect their lung function eventually causing delays in the activation of the immune system as a result; the virus can replicate, produce extra symptoms and increases the death rate.

When should you see a doctor?

You should get instant medical treatment if you have these warning signs:

  1. Worsening difficulty in breathing
  2. Continuous pain or pressure in the chest 
  3. New onset of confusion
  4. Blue lips, face, and fingers
  5. Dizziness and failure to wake up after sleep

You should also seek doctors’ help when you already have any underlying conditions or you are pregnant while you develop a COVID-19 infection.


COVID-19 is a highly contagious disease that is evident in a variety of symptoms. Since the presentation may differ from being asymptomatic (no symptoms) to severely ill, it is really important to quickly identify the symptoms for early detection and seek medical care timely. Special attention is required for people with underlying diseases and they must be monitored carefully for indicators to avoid getting into further difficulties. It is also recommended to be vaccinated against COVID-19 to prevent potential complications. 


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  3. Coronavirus disease (COVID-19): symptoms, causes & prevention [Internet]. Cleveland Clinic. [cited 2022 Oct 19]. Available from:
  4. Elliott J, Whitaker M, Bodinier B, Eales O, Riley S, Ward H, et al. Predictive symptoms for COVID-19 in the community: REACT-1 study of over 1 million people. PLOS Medicine [Internet]. 2021 Sep 28 [cited 2022 Oct 19];18(9):e1003777. Available from:
  5. Semenzato L, Botton J, Drouin J, Cuenot F, Dray-Spira R, Weill A, et al. Chronic diseases, health conditions and risk of COVID-19-related hospitalization and in-hospital mortality during the first wave of the epidemic in France: a cohort study of 66 million people. The Lancet Regional Health – Europe [Internet]. 2021 Sep 1 [cited 2022 Oct 19];8. Available from:
  6. Targher G, Mantovani A, Wang XB, Yan HD, Sun QF, Pan KH, et al. Patients with diabetes are at higher risk for severe illness from COVID-19. Diabetes Metab [Internet]. 2020 Sep [cited 2022 Oct 19];46(4):335–7. Available from:
  7. Who is at high risk for severe coronavirus disease? [Internet]. 2022 [cited 2022 Oct 19]. Available from:
  8. Beltramo G, Cottenet J, Mariet AS, Georges M, Piroth L, Tubert-Bitter P, et al. Chronic respiratory diseases are predictors of severe outcome in COVID-19 hospitalised patients: a nationwide study. European Respiratory Journal [Internet]. 2021 Jan 1 [cited 2022 Oct 19]; Available from:
  9. Sharma AK, Baig VN, Sharma S, Dalela G, Panwar RB, Katoch VM, et al. Cardiovascular risk factors and outcomes in COVID-19: A hospital-based study in India. PLOS Global Public Health [Internet]. 2022 Apr 1 [cited 2022 Oct 19];2(4):e0000234. Available from:
  10. Fung M, Babik JM. Covid-19 in immunocompromised hosts: what we know so far. Clin Infect Dis [Internet]. 2020 Jun 27 [cited 2022 Oct 19];ciaa863. Available from:
  11. Arya A, Li M, Aburjania N, Singh P, Royer T, Moss S, et al. Covid-19 in solid organ transplantation: disease severity and clinical update. Transplant Proc [Internet]. 2021 May [cited 2022 Oct 20];53(4):1227–36. Available from:
  12. Rustagi V, Bajaj M, Tanvi, Singh P, Aggarwal R, AlAjmi MF, et al. Analyzing the effect of vaccination over covid cases and deaths in asian countries using machine learning models. Front Cell Infect Microbiol [Internet]. 2022 Feb 8 [cited 2022 Oct 20];11:806265. Available from:
  13. CDC. Benefits of getting a covid-19 vaccine [Internet]. Centers for Disease Control and Prevention. 2022 [cited 2022 Oct 20]. Available from:
  14. Ho FK, Petermann-Rocha F, Gray SR, Jani BD, Katikireddi SV, Niedzwiedz CL, et al. Is older age associated with COVID-19 mortality in the absence of other risk factors? General population cohort study of 470,034 participants. PLOS ONE [Internet]. 2020 Nov 5 [cited 2022 Oct 20];15(11):e0241824. Available from:

Amira Samnani

Bachelor of Science in Nursing- The Aga Khan University Hospital, Pakistan

Amira is a Registered Nurse with demonstrated clinical experience of working in health care industry. She has a 4 years of experience as a practicing nurse in Internal Medicine-Adult care unit. She is proficient in her knowledge about health education and promotion. Currently, she is seeking roles in her field while continuing her education to become health and wellness expert. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
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