I don’t know much about veins like this but aren’t these big bloated veins under serious pressure and couldn’t they blow at any second?
Can get a blood clot & it can travel to say your lungs or heart.
Deep vein thrombosis (DVT) is a serious condition with blood clots in the deep veins. This condition does not usually happen with varicose veins. That is because varicose veins affect the veins close to the surface of the skin. However, with severe varicose veins, there is a small chance of developing blood clots in the deep veins. Blood clots need medical care right away. Symptoms of blood clots include pain, swelling, and redness of the leg. Blood clots may also happen in the arms or other parts of the body. If you have symptoms that may mean a blood clot, call your healthcare provider.
A piece of a blood clot may break off and travel to the lungs (pulmonary embolism). A blood clot in the lungs is very serious and may cause death. Symptoms include chest pain, trouble breathing, coughing (may cough up blood), a fast heartbeat, sweating, and fainting. If you have symptoms that may mean a blood clot in the lungs, call 911 or get emergency help.