Understanding Blood Clots: Causes, Risks, and Prevention


Anyone who has experienced a scraped knee understands the body’s natural ability to stop bleeding through blood clot formation. These clots play a crucial role in stemming blood flow from wounds, but they can also pose risks when they occur internally.

Internal blood clots fall under the medical term “venous thromboembolism” (VTE). There are two primary forms:

1. **Deep Vein Thrombosis (DVT):** This occurs when a clot forms in a deep vein, often in the leg. Symptoms include warmth, redness, tenderness, and cramping sensations in the affected area. DVT can lead to a complication called pulmonary embolism (PE).


2. **Pulmonary Embolism (PE):** Arising from a DVT, a PE happens when a clot dislodges and blocks a lung’s blood supply. Symptoms involve sudden shortness of breath and chest pain.

VTEs are relatively common, affecting over 900,000 individuals annually, according to CDC estimates. Diagnoses rely on symptom assessment, imaging, and blood tests.

**Risk Factors for Blood Clots:**

Understanding the risk factors for VTE is crucial due to their potentially fatal consequences. The Society for Vascular Medicine categorizes these risks into five main groups:

1. Immobility: Extended periods of immobility, whether from hospitalization or prolonged sitting during travel, increase risk. Regular movement and exercise can counteract this risk.

2. Surgery or Trauma: Orthopedic surgeries and injuries trigger clotting as part of the body’s healing process. Exaggerated clot responses can result in VTEs.

3. Increased Estrogen: Hormonal factors like birth control, pregnancy, and hormone replacement therapy elevate VTE risk.

4. Medical Conditions: Certain diseases, such as cancer and inflammatory disorders, contribute to VTE vulnerability.

5. Lifestyle and Genetics: Family history of clotting disorders, age over 60, smoking, obesity, and a sedentary lifestyle raise the likelihood of VTE occurrence.