Blood clots are made when substances in the blood thicken and form a semisolid mass. This process may be triggered by an injury. Sometimes it occurs inside blood vessels that don't have an obvious injury.

Once these clots form, they can travel to other parts of the body where they can cause harm. There are a variety of factors and conditions that can cause troublesome blood clots, and there are some serious conditions that are associated with blood clots. These include:

  1. Antiphospholipid syndrome
  2. Arteriosclerosis / atherosclerosis
  3. Cancer
  4. Certain medications, such as oral contraceptives and hormone therapy drugs
  5. Coronavirus disease 2019 (COVID-19)
  6. Deep vein thrombosis (DVT)
  7. Factor V Leiden
  8. Family history of blood clots
  9. Heart arrhythmia (heart rhythm problems)
  10. Heart attack
  11. Heart failure
  12. Obesity
  13. Peripheral artery disease (PAD)
  14. Polycythemia vera
  15. Pregnancy
  16. Prolonged sitting or bed rest
  17. Pulmonary embolism — a blood clot in an artery in the lung.
  18. Smoking
  19. Stroke
  20. Surgery

Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.

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July 19, 2023