Full-dose Blood Thinners Could Prevent COVID-Related Clotting in Hospitalized Patients


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Key Takeaways

  • Anyone who had COVID-19 is at a higher risk of developing blood clots for months after recovery, a study shows.
  • For critically ill COVID-19 patients, a full-dose blood thinner can lower the risk of severe blood clots without increasing the risk of death.
  • To prevent blood clot formation after a COVID-19 infection, experts recommend staying active and paying attention to any warning signs.

Anyone who has had COVID-19—even if it was a mild case—is at a higher risk of developing blood clots for months after recovery. If untreated, blood clot complications such as deep vein thrombosis and pulmonary embolism can cause serious damage to the heart or lungs.

A new study found that full-dose blood-thinning medications might help reduce the risk of blood clots in critically ill COVID-19 patients.

Typically, hospitalized COVID-19 patients might be given a relatively low dose of blood thinner to prevent blood clots, as a high dose might lead to severe bleeding. The study showed that a full-dose blood thinner did increase bleeding, but it didn’t increase the risk of death.

Ankit Shah, MD, an assistant professor at Rutgers New Jersey Medical School, told Verywell that the risk of life-threatening blood clots from COVID-19 appears to be lower now with more advanced treatment and milder variants.

He said the study findings suggested that patients in the ICU should be considered for full-dose anticoagulation, “but we need to individualize this decision based on the patient’s risk of clotting and bleeding.”

For instance, if a patient has a recent bleeding event, it may not be the best idea to give the full-dose blood thinner, Shah added.

How Can You Prevent Post-COVID Blood Clots? 

While hospitalized COVID-19 patients may receive blood thinners as part of their preventive treatment, most people won’t need this medication, Shah said.

“Only certain high-risk patients, such as those with previous blood clot, surgery, trauma, or immobilization should be considered for continued anticoagulation [upon discharge,]” he said.

According to Mark Loafman, MD, MPH, chair of the family and community medicine department at Cook County Health, said the rate of serious blood clot formation after a COVID-19 recovery seems to be decreasing over time, which is likely due to vaccinations.

A recent study published in JAMA Internal Medicine found that the risk of blood clots was substantially lower in people who were fully vaccinated.

After recovering from a COVID-19 infection, you can try to prevent blood clots by staying active and moving around.

“To decrease the risk of blood clot formation, we always encourage maintaining regular minimal activity like walking, stretching, light aerobic activity,” Loafman said. “In many cases, clot development is a gradual process, so any unexplained, unilateral leg or arm swelling should prompt a visit to your doctor or emergency department that same day.”

What This Means For You

Anyone who had COVID-19 is at a higher risk of developing blood clots for months after recovery. Watch out for signs of blood clots, such as swelling in the arm or leg, and contact your healthcare provider immediately.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Katsoularis I, Fonseca-Rodrí­guez O, Farrington P, et al. Risks of deep vein thrombosis, pulmonary embolism, and bleeding after covid-19: nationwide self-controlled cases series and matched cohort study. BMJ. 2022;377:e069590. doi:10.1136/bmj-2021-069590

  2. Bohula EA, Berg DD, Lopes MS, et al. Anticoagulation and antiplatelet therapy for prevention of venous and arterial thrombotic events in critically ill patients with COVID-19: COVID-PACT. Circulation. Published online August 29, 2022. doi:10.1161/CIRCULATIONAHA.122.061533

  3. Xie J, Prats-Uribe A, Feng Q, et al. Clinical and genetic risk factors for acute incident venous thromboembolism in ambulatory patients with COVID-19. JAMA Intern Med. Published online August 18, 2022. doi:10.1001/jamainternmed.2022.3858

By Carla Delgado
Carla M. Delgado is a health and culture writer based in the Philippines.