Linking COVID-19 and Processes Leading to Blood Clots
Severe cases of COVID-19 can lead to an increased risk of blood clots, according to medical research. While the occurrence of blood clots as a result of a COVID-19 diagnosis is relatively uncommon, the inflammation triggered by the immune system's response to the virus can cause vascular endothelial damage, dysregulation of the coagulation system, and intense immune responses that promote inflammation-driven thrombosis.
This inflammatory state leads endothelial cells to shift from an antithrombotic to a prothrombotic phenotype, activating the coagulation cascade and amplifying cytokine release and platelet activation. Neutrophil extracellular traps (NETs) further contribute to local thrombin production and coagulation activation, enhancing clot formation.
Several factors contribute to the risk of blood clots in COVID-19 patients. These include vascular endothelial injury caused by the virus, a dysregulated coagulation system, virus-induced immune and inflammatory responses, activation of protease-activated receptors promoting thrombosis-inflammation feedback, and NET formation facilitating coagulation cascade activation.
Certain populations are more vulnerable to COVID-19-associated blood clots. These include patients with severe COVID-19 illness who exhibit higher inflammatory and vascular dysfunction markers. Additionally, individuals with pre-existing conditions linked to thrombosis risk, such as cancer—especially blood cancers like leukemia and lymphoma, those undergoing chemotherapy or immunosuppressive treatments, and lung cancer patients—are at higher risk due to weakened immune systems and a higher susceptibility to severe infection.
Patients with known clotting disorders, autoimmune diseases, or those on certain hormonal therapies may also have an elevated risk, though absolute risks remain low. Other risk factors consistent with general blood clot risk, such as hospitalization, surgery, immobility, and genetic predisposition, also apply.
The risk of blood clots remains elevated for nearly a year after getting COVID-19. The risk is highest within the first week after a COVID-19 diagnosis and for those hospitalized with the illness. Researchers suggest that vaccinations and improvements in COVID-19 treatment may have decreased blood clot cases.
A blood clot can block blood flow to essential organs like the lungs (causing a pulmonary embolism) or the brain (causing a stroke). COVID-19 patients may develop a symptom called "COVID toes" which are red, swollen toes often attributed to small clots in the blood vessels of the feet. Chronic health conditions, such as coronary artery disease, diabetes, high blood pressure (hypertension), obesity, blood disorders like sickle cell disease or thalassemia, can increase the risk of blood clot issues from COVID-19.
High levels of inflammation in response to COVID-19, according to the National Heart, Lung and Blood Institute (NHLBI), may cause blood clots. COVID-19 patients, particularly those hospitalized or with certain risk factors, may benefit from therapies to prevent blood clots, such as blood-thinning medications, compression gear, and movement. In the legs, swelling is the most common sign of a blood clot.
It's important to understand the risk of blood clots from COVID-19 and discuss preventive strategies with a healthcare provider. However, there's no reason to panic about blood clots from COVID-19.
- Severe travel restrictions may be necessary for individuals with chronic diseases or medical-conditions, as they are at a higher risk of blood clots due to the immune system Response to the virus in COVID-19 cases.
- Due to the risk of blood clots associated with COVID-19, health-and-wellness practices such as CBD (Cannabidiol) could potentially be explored as an alternative medicine to help manage inflammation and reduce the risk of blood clot formation.
- Scientific research indicates that patients diagnosed with COVID-19 might face an increased risk of blood clots for nearly a year, with those in hospitalized conditions presenting the highest risk.
- The inflammatory state caused by COVID-19 triggers a shift in endothelial cells, promoting the activation of the coagulation cascade, cytokine release, platelet activation, and neutrophil extracellular traps (NETs) production, which all contribute to blood clot formation.
