I was asked by a friend to explain how an acquaintance had died suddenly from a blood clot. This is overwhelmingly due to blood clots in veins below the waist forming a clot which breaks loose and lodges in the lungs. The name is venous thromboembolism (venous thrombo=clotting, embolism=traveling). It is an important and deadly condition.
The number of people having clots form in their legs is estimated at 900,000 per year and the pulmonary embolism results in estimates of up to 100,000 deaths yearly. The causes were described by one of the most famous physicians of the 19th century; he was Rudolph Virchow (1821 to 1902), a German pathologist. He described the three predisposing factors: Slowed circulation, increased clotting (hypercoagulability to the informed), and damage to the lining of the blood vessels. These are to be avoided in as much as possible.
Slowed circulation is almost certainly the most common causal factor in thrombosis of the veins which is most often in the legs. We have two sets of leg veins: superficial which are visible and drain the skin and deep which are not visible and drain the muscles. Clots in the deep veins are the dangerous ones. Inactivity is the principal cause of slowed circulation.
It is another of the remarkable engineering feats of creation design. The heart propels arterial blood but veins are beyond the propulsion’s reach. Instead, the muscles of the legs when contracted squeeze the contained blood during walking and valves keep the blood going back to the heart during relaxation! Sitting for prolonged periods such as bed rest slows the circulation, setting the stage for clots. Also, a dangerous situation is on long airplane flights. The government mentions flights over 4 hours as being dangerous. I try to briefly walk the aisles every hour to be on the safe side. One can also move legs while seated especially the calf muscles by raising the heels are far as you can or bringing the knee toward the chest periodically.
Increased clotting can be from genetic or acquired conditions. If one has relatives that have had clots, have clots in unusual places such as the arms, or have repeated clots – they should be evaluated by a physician. Predisposition is in people over 60 years, obesity, recent surgery, or marked dehydration. Ways you can keep your blood staying thinner is to drink enough water. A good rule of thumb is to drink 8-8ounce glasses of liquid daily.
There is a thin layer lining the vessels and heart called endothelium (endo=inner, thelium= nipple?) which serves as the Teflon of our bodies. This lining is composed of the only cells that when blood is in contact that it does not clot. This lining can become damaged as we age and expose tissue that can stimulate clotting.
Signals of possible deep vein thrombosis are: when one leg or more rarely an arm becomes swollen, tender without cause, or reddened. Get checked out! Keep Safe.