Blood Clots and COVID-19

COVID-19 is an illness which is caused by the coronavirus, SARS-COV-2. Cough and shortness of breath are some of its classic symptoms that can affect the respiratory system and can affect other parts of the body as well like loss of smell or taste, rashes or any gastrointestinal symptoms. In the second wave specifically, a new possible side effect of COVID-19 is that it can lead to blood clots in some people, but is emerging as the new dangerous effect of the illness.

How are blood clots formed?

Formation of blood clots

  • When there is an injury to the blood vessel, proteins are produced which attract platelets and other clotting factors resulting in the formation of a clot that can plug the injury to the blood vessel and helps in healing.
  • These blood clots can sometimes even form in the absence of an injury, which is potentially dangerous as the clot can restrict the blood flow within the blood vessels which can lead to a complication like a stroke or a heart attack.

Can COVID-19 cause blood clots?

When a patient is infected with COVID, the virus damages the vessels of any of the lungs leading to clotting (thrombosis) of vessels which can lead to sudden death. This virus  can attack both the venous and the arterial system leading to a poor outcome. Deep Vein Thrombosis (DVT) is a clot in the vein and is typically identified with severe pain , redness and discoloration of skin, this can travel to the lung and cause a condition namely Pulmonary Thromboembolism (PTE), which is a probable cause of sudden death.

Who is at a higher risk for developing blood clots?

  • People who are infected by the deadly coronavirus and are hospitalized.
  • COVID-19 patients with 30-50 % of infection have a tendency of vascular clotting. 
  • Other conditions :  Diabetes, smoking, obesity, hypertension, pregnancy, immunocompromised patients, kidney failures.


Which Complications can lead to blood clots?

A blood clot in a body can lead to some severe complications like:

  • Heart attack– which happens when the blood flow to the heart tissue is reduced or cut off leading to a possible heart attack.
  • Brain stroke – when there is a blood clot in the blood vessels of a brain, it interferes with the blood flow which leads to a stroke. If there is a reduced blood flow due to a temporary clot , it can lead to a ministroke or a transient ischemic attack (TIA).
  • Pulmonary embolism- when a blood clot travels to the lungs and blocks the blood flow, leading to decreased oxygen levels and damage to the tissues of the lung.

A blood clot can even restrict blood flow in the other parts of the body as well leading to severe damage. The other areas that can get affected are:

  • Limbs
  • Kidneys
  • Gastrointestinal tract

How does COVID-19 affect the capillaries?

Capillaries are the smallest blood vessels in the body . These capillaries are very narrow due to which the red blood cells need to pass through them in a single fine line.

  • A blood clot in a COVID-19 patient can also affect the capillaries and due to the presence of these tiny clots in capillaries a condition is seen called “COVID toes”. These tiny clots can be dangerous.
  • In patients with the COVID-19 pneumonia condition, there is difficulty in breathing due to the inflammation and fluid buildup as these tiny clots in the capillaries inside the tiny air sacs of the lungs can restrict the blood flow leading to decreased oxygen levels.


What are the treatment options?

Blood clots are often treated with medication called blood thinners, which reduces the clotting in the body and can prevent existing clots from getting bigger and does let new clots form.

  • Patients who have recovered from Covid infection are advised to continue blood thinners for at least 3 months.
  • For initial treatment, it is  advised that patients have “timely referral to a vascular surgeon who can save the life and limb of patients with severe blood clots. An early detection of these clots can help and can  be managed with simpler procedures like embolectomy, which can be done under local anaesthesia, at bedside for very sick patients. Percutaneous procedures and thrombolysis can also be an option in a few cases. 
  • Patients with moderate to severe covid infection can be discharged on anticoagulation to avoid these catastrophic events of limb loss and permanent disability.

How can blood clots be prevented?

  • Patients with pre-existing vascular issues or with Covid infection should take more precautionary measures such as keeping adequate hydration and active mobilization. 
  • Staying active- Regular exercise is advised to decrease the risk of a blood clot.Taking regular physical breaks can keep one away from a sedentary lifestyle.
  • Being fit and shedding some extra kilos can always help in lowering the risk from developing a blood clot.
  • Quit smoking as it can damage the lining of the blood vessels and can cause blood clots.
  • Intake of prescribed medicines only as some types of medications like birth control pills, hormone replacement therapy or even certain drugs have side effects and can increase the risk of blood clots. Always consult your doctor before taking any medicine.

The best way one can prevent these blood clots along with COVID-19 is to take sincere steps in avoiding contracting the new coronavirus.

Some effective steps that can help from contracting this highly contagious virus is to:

  • Maintain Physical distance
  • Maintain distance from people who are sick
  • Washing hands frequently
  • Wash hands before touching the nose, mouth and eyes.
  • Always wear a mask when around people.

It is always advised to speak to a doctor regarding COVID-19 or any blood clot risk. Covid-19 can cause blood clots, and is found in individuals who are hospitalized due to this extreme Covid infection. Though it is still unclear how Covid-19 can prompt a blood clot, but, the disease has been found to initiate cells that are associated with the blood clotting process. Blood clots because of Covid-19 can prompt complications like stroke and coronary failure and this can happen across all age groups.


About Author –

Dr. Devender Singh, Consultant Vascular & Endovascular Surgeon, Yashoda Hospital

best Vascular Surgeon in hyderabad

Dr. Devender Singh

MS, DNB (Vascular Surgery)
Consultant Vascular & Endovascular Surgeon

Select Department
Not Sure of the Specialty?

Choose your date & Slot

Change Date
Monday, OCTOBER 30
Enter Patient Details

Please Note: This session ends in 3:00 mins

Not Finding Your Preferred Slots?
Change Doctor
or Location
top hospital in hyderabad
Call Helpline
040 - 4567 4567