当血液的某些组分变稠，形成半固态团块时，血凝块形成。这个过程可能由损伤诱发，有时也可能在无明显损伤的血管内部出现。
一旦这些血凝块形成，可能会行进至身体的其他部分，从而造成伤害。有多种因素和状况会导致出现产生令人担忧的血凝块，以及与血凝块有关的严重医疗状况。包括：
- 抗磷脂综合征
- 动脉硬化/动脉粥样硬化
- 癌症
- 某些药物，如口服避孕药和激素治疗药物
- 2019 冠状病毒病（COVID-19）
- 深静脉血栓（DVT）
- 凝血因子 V 莱顿突变
- 血栓家族病史
- 心律不齐 （心律问题）
- 心脏病发作
- 心力衰竭
- 肥胖症
- 外周动脉疾病（PAD）
- 真性红细胞增多症
- 怀孕
- 久坐或长期卧床
- 肺栓塞 — 肺内动脉有血凝块。
- 吸烟
- 卒中
- 手术
下面列出了与该症状有关的常见病因。请与您的医生或其他医疗中心的专家配合，寻求更准确的诊断结果。
- Blood clots. American Society of Hematology. https://www.hematology.org/education/patients/blood-clots. Accessed April 23, 2023.
- Your guide to preventing and treating blood clots. Agency for Healthcare Research and Quality. https://www.ahrq.gov/patients-consumers/prevention/disease/bloodclots.html. Accessed April 23, 2023.
- Loscalzo J, et al., eds. Bleeding and thrombosis. In: Harrison's Principles of Internal Medicine. 21st ed. McGraw Hill; 2022. https://accessmedicine.mhmedical.com. Accessed April 23, 2023.
- Understand your risk for excessive blood clotting. American Heart Association. https://www.heart.org/en/health-topics/venous-thromboembolism/understand-your-risk-for-excessive-blood-clotting. Accessed April 23, 2023.
- Blood clotting disorders: Causes. National Heart, Lung, and Blood Institute. https://www.nhlbi.nih.gov/health/clotting-disorders/causes. Accessed April 23, 2023.
- What is venous thromboembolism? Centers for Disease Control and Prevention. https://www.cdc.gov/ncbddd/dvt/facts.html. Accessed April 23, 2023.
- Loscalzo J, et al., eds. Arterial and venous thrombosis. In: Harrison's Principles of Internal Medicine. 21st ed. McGraw Hill; 2022. https://accessmedicine.mhmedical.com. Accessed April 23, 2023.
- Caforio ALP. COVID-19: Cardiac manifestations in adults. https://www.uptodate.com/contents/search. Accessed April 23, 2023.