In most cases, pulmonary embolism is caused by a blood clot in the leg that breaks loose and travels to the lungs. A blood clot in a vein close to the skin is not likely to cause problems. But having blood clots in deep veins (deep vein thrombosis) can lead to pulmonary embolism.
St. Petersburg. 1  St. Petersburg is a city with a long and eventful history. 2  Altai is perhaps the most beautiful region of Russia. 3  Moscow is the capital of Russia, as well as the nationâs epicentre of arts, music, science, academics, and politics.  For a step back in time, Olkhon Island is a wonderful place to visit.
Samara (Russian: Ð¡Ð°Ð¼Ð°ÑÐ°; IPA: ), known from 1935 to 1991 as Kuybyshev (ÐÑÐ¹Ð±ÑÑÐµÐ²; IPA: [ËkujbÉ¨ÊÉf]), is the sixth largest [4] city in Russia and the administrative center of Samara Oblast.