Any number of situations can increase a person's risk for developing blood clots. Blood clots form when plasma proteins (factors) and components of blood like platelets thicken or slow in the blood vessels, causing a mass. Blood clots often form following an injury or a surgical procedure to aid in healing.
Blood clots that break off in a vein or artery can contribute to a number of serious and sometimes deadly conditions such as a pulmonary embolism (PE) or a stroke.
Primary causes of blood clots
According to the Mayo Clinic, a handful of the top offenders include:
- Age – individuals over 60 years of age are at an increased risk of developing a deep-vein thrombosis (blood clot known as DVT). The jury is still out on exactly why/how this happens.
- Obesity – being overweight or obese adds additional pressure to muscles and blood vessels of the lower extremities. Combined with other lifestyle risks, weight issues can increase risk of blood clot formation due to poor circulation.
- Sedentary lifestyle/prolonged inactivity – sitting for long periods of time increases the risk of development of a DVT.
- Smoking – damages interior lining of blood vessels, giving blood components a better chance of 'grasping' into that damaged area and forming a blood clot.
- Pregnancy – contributes to hormonal and chemical surges in the body. Coupled by reduced activity during the third trimester, blood clot formation is a possibility.
Sometimes, blood clots are caused by a medical condition or dysfunction of the circulatory system in the body. For example:
- Heart failure, heart rhythm problems, or previous history of heart attack.
- Atherosclerosis/arteriosclerosis - caused by narrowed blood vessel walls, prompting blood to become sluggish or slow down, increasing the potential of a blood clot forming.
- Medications including hormone therapy drugs and oral contraceptives, among others. Combining hormone therapy medications with birth control drugs increases risk due to concerns that high levels of estrogen increases blood clotting factor levels in the body.
- Peripheral artery disease – causes narrowing of blood vessels serving the extremities, and like atherosclerosis, causes sluggish blood flow.
- An injury or surgery – may damage blood vessels, which promotes formation of blood clots to heal and repair. However, inactivity increases risk of increased blood clot formation. (That's why you need to ambulate as soon as possible following a surgical procedure.)
Additional risks have to do with family history, a diagnosed blood disorder, or past experience with a DVT, stroke, or heart issue. Talk to your doctor about risks associated with potentially dangerous blood clots and how you can decrease your risk.