Over the weekend, John had developed a cough. He thought he had a cold coming on, but now he couldn’t catch his breath. He went to his primary doctor and she didn’t like the sound of it. John was not a complainer, and she first did a blood test that showed that his clotting system had been activated. She promptly followed up with a scan of his lungs, which showed a number of blood clots in the arterial system of his lungs. He urgently needed the clots dissolved and was admitted to the hospital.
What causes blood to clot where it shouldn’t? Blood needs to clot when there is a tear in the blood vessels, to plug the hole. But it should not clot inside an intact blood vessels system otherwise it won’t circulate. The clotting system is in fine balance with the anti-clotting system.
What causes blood to clot inside an intact system? Poor circulation can be caused by physical obstruction or by immobility. When patients are bedridden either due to an operation or an illness, they are at risk for blood pooling in their lower legs and clotting. They are often given blood thinners for clot prevention. Similarly, a long airplane ride or a long car ride when we are confined for hours, in combination with not drinking enough water to avoid bathroom trips, or drinking alcohol on a plane adds to dehydration and a risk for a blood clot. Some illnesses can weaken the anticlotting system and the clotting system works unchallenged. Some medicines can predispose to clots, like estrogen. Or they can uncover a hidden genetic defect in the anticlotting system.
When someone develops a blood clot in their venous or arterial system, doctors mostly investigate for problems in their blood vessels or in their clotting system. They look for autoimmune disorders, genetic mutations in the clotting or anticlotting proteins. By process of elimination, they try to find the cause of the blood clot.
What if they don’t find any cause? This falls in the category of an unprovoked blood clot. In this case a reasonable effort should be made to find a hidden or occult cancer. Cancer cells produce substances that can unbalance the anticlotting system, or make the blood cells stickier. Tumors can push on blood vessels and impede the flow of blood. Thus far, clots in the veins have been known to be harbingers of hidden cancers, now a study shows that clots in the arterial system can also be the canary in the coal mine. Any clot that doesn’t have an obvious trigger deserves an investigation for cancer.
https://www.jwatch.org/na48679/2019/03/11/arterial-thrombosis-and-occult-cancer?ijkey=Bhs7AATVo&query=jwonchub