Blood clots, or thrombi, are a common medical condition that can lead to serious health problems such as heart attack, stroke, deep vein thrombosis (DVT), or pulmonary embolism (PE).1,2 Thrombosis is the formation of blood clots in the circulatory system, which can occur due to various factors such as injury to the vessel wall, decreased blood supply, or increased clotting factors.2 Thrombi consists of fibrin, platelets, and trapped red and white blood cells.3 The main protein component of blood clots, fibrin, is generally formed from fibrinogen by the action of thrombin.4 Hemostasis, the process of blood clot formation, is a coordinated series of responses to vessel injury that requires complex interactions between platelets, the clotting cascade, blood flow, endothelial cells, and fibrinolysis.5 The formation of blood clots is a physiological process within the body and can help prevent excess blood loss from a damaged vessel. However, thrombi can be a matter of concern as they may cause stroke, heart attack, DVT, or PE.

According to the Centers for Disease Control and Prevention (CDC), as many as 900,000 people in the United States are affected by a blood clot each year.6 Among those in the population who have had a DVT, approximately a third will have chronic complications such as swelling, pain, and discoloration.6 Various risk factors are associated with blood clots. Adults with pre-existing chronic health conditions such as cardiovascular disease, lung disease, inherited clotting disorders, hypertension, or spinal cord injuries are three times more likely to be diagnosed with a DVT.7 Other risk factors include obesity, cigarette smoking, long travel, immobilization, surgery, and medications such as oral contraceptives.8

The symptoms of a blood clot depend on the location. Common symptoms of a DVT include swelling, pain, tenderness, and redness of the skin surrounding the site of the clot.6 Signs and symptoms of PE include difficulty breathing, tachycardia, chest pain, hypotension, and hemoptysis. If diagnosed early, blood clots can be managed. Medications may be used to treat and prevent blood clots. Thrombolytics are a type of medication that can dissolve a clot.6 Anticoagulants may be prescribed to prevent future clots from forming.6 In addition to medication, compression stockings may be advised if a patient is at risk for a DVT. The risk of blood clots can be reduced by maintaining a healthy weight, avoiding a sedentary lifestyle, and avoiding prolonged immobilization.6

Recent studies have shown that COVID-19 is associated with a significant coagulopathy, leading to increased rates of both venous and arterial thromboembolic events.9 COVID-19 has been linked to increased risk of blood clots, including pulmonary embolism, DVT, peripheral arterial thrombosis, and acute ischemic stroke.9–11 The pathogenesis of a COVID-19 induced hypercoagulable state is not fully understood, but it is believed to be due to direct invasion of endothelial cells by SARS-CoV-2 and subsequent release of inflammatory cytokines, coupled with various coagulation abnormalities.12 The inflammatory response and coagulopathy associated with COVID-19 are linked, and endothelial injury as well as augmented immune response are implicated in the development of diffuse macro- and microvascular thrombosis.9,13 Patients with COVID-19 have a higher incidence of thrombosis, and thromboembolic complications are associated with severe COVID-19 and high mortality.13


A 47-year-old female sought care for neck, upper back, and left ankle pain. She attributed the upper trunk pain to being inactive due to having COVID-19. She was unvaccinated and reported being bedridden for 2 weeks at home. She claimed to have twisted her left ankle about 6 weeks earlier, but the injury had since resolved. After recovering from COVID-19, she reported the ankle pain worsened and began traveling into the calf. She was seen by her primary care physician (PCP) via telehealth for her ankle complaint but felt that her concerns were dismissed as being related to the previous injury. Using the Visual Analog Scale (VAS), the patient rated her pain in the neck, upper back, and left ankle at 8/10. She reported that the neck and upper back pain were intermittent and radiated into the anterior left arm. The left ankle pain was constant and described as aching, throbbing, and tight. No palliative remedies were reported for the left ankle, but almost any movement was provocative.

Objective examination of the cervical and thoracic regions identified joint restriction at C4-C7 and T3-T7. Soft tissue palpation revealed hypertonicity of the left trapezius and bilateral thoracic paraspinal musculature. Additionally, active trigger points were located in the quadratus lumborum, thoracic paraspinals, rhomboids, upper trapezius, and levator scapulae bilaterally but worse on the right. Cervical extension and left rotation ranges of motion were moderately decreased and painful. Thoracic flexion and extension were moderately decreased and painful. The following orthopedic tests were positive for pain without radiation: Spurling’s Test, Maximum Foraminal Compression Test bilaterally, and Soto-Hall Test. Visual inspection revealed significant swelling and edema around the left ankle and the posterior lower leg. All ankle ranges of motion were painful and significantly reduced.

Initial treatment of the spinal complaints consisted of passive modalities including moist heat, electrical muscle stimulation, and ultrasound in addition to chiropractic manipulative therapy (CMT). Due to suspicion of a potential blood clot in the left leg, the patient’s PCP was consulted, and an ultrasound was scheduled for the following morning.

Doppler ultrasound evaluation was performed to assess the bilateral external iliac, left common femoral, deep femoral, femoral, popliteal, posterior tibial, and peroneal veins. The ultrasound confirmed DVT extending from the common femoral vein inferiorly through the popliteal vein and tibioperoneal trunk. In the calf, there were occlusive and nonocclusive thrombi within the upper and mid posterior tibial and peroneal veins. The overall impression of the Doppler ultrasound was extensive DVT involving the left lower extremity. The patient was treated with anticoagulants and rest, and the clots resolved within several months.


This case describes the presentation of DVT in a patient with neck, upper back, and ankle pain after recovering from COVID-19 and being on bedrest for two weeks. Common symptoms of a DVT include swelling, cramping, pain, tenderness, and redness of the skin surrounding the site of the clot.6 A chiropractor may suspect a DVT based on the symptoms, history, and physical examination. DVT can be confirmed through blood test results (D-dimer test) and imaging. Early diagnosis and treatment are critical for DVT as it is the third most common cause of death from cardiovascular disease after cardiac infarction and ischemia.14 Two major complications following a DVT include PE and post-thrombotic syndrome (PTS). PE occurs when a piece of the DVT travels through the bloodstream to the lungs. Symptoms and fatality depend on the size of the clot. PTS is a chronic consequence of DVT that affects up to 50% of patients.15 Clinical indications of PTS vary from mild to severe symptoms such as chronic debilitating leg pain, uncontrolled edema, and leg ulcers.15

Recent studies have shown that COVID-19 is associated with increased rates of both venous and arterial thromboembolic events.9 Understanding the relationship between COVID-19 and blood clots is crucial for clinicians due to the potential thrombotic complications associated with the virus. COVID-19 has been found to increase the risk of thrombotic events, including deep vein thrombosis and pulmonary embolism.14 There is emerging evidence that COVID-19 acts as a blood clotting disorder, with the virus using the respiratory route to enter the bloodstream.15 It is important for healthcare providers to differentiate between COVID-19 related blood clots and other disorders, as the symptoms can overlap and have life-threatening consequences.

Additionally, understanding the relationship between COVID-19 and blood clots can aid in the prevention and management of these complications. While antiviral and immune therapies are undergoing investigation, the role of blood thinners in preventing and managing blood clots in COVID-19 patients needs further evaluation.15 It is also important to note that the relationship between COVID-19 and blood clots is not limited to arterial and venous thrombosis. The spike protein of the virus can bind to the blood coagulation factor fibrinogen, leading to the formation of abnormal blood clots with elevated proinflammatory activity.16 Overall, a comprehensive understanding of the relationship between COVID-19 and blood clots is essential for clinicians to effectively manage and treat patients.

A meticulous history and examination must include age, history of present illness, past medical and family history, medications, recent trauma, and recent activity levels. This case presentation had the physical symptoms of a DVT, as well as lack of movement over the past two weeks due to COVID-19. A detailed history and physical exam are critical, as 50% of patients with a DVT will not experience pain and 30% will not present with swelling.14 Although chiropractors do not typically treat DVT, it is imperative to recognize the signs and symptoms of this condition and make a proper referral. Interprofessional communication and care coordination are pivotal to managing and lowering the morbidity of DVT.


This is a single-patient case report and the results may not be generalizable to other individuals presenting with similar conditions.


Understanding the relationship between COVID-19 and blood clots is crucial for clinicians due to the potential thrombotic complications associated with the virus. It is important for healthcare providers to differentiate between COVID-19-related blood clots and other disorders, as symptoms can overlap with life-threatening consequences.

Written consent for publication was obtained from the patient.


The authors declare no competing interests.