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.
If you're looking for the most complete Russia travel experience, consider river cruises. Why? For the price of a week long tour of just Moscow & St. Petersburg you see and experience so much more. Explore the hidden gems of Russia like UNESCO listed Kizhi Cathedral and Uglich - a small town known as the Vatican of Russian Church. On top of that, stay in best downtown hotels in Moscow & St. Petersburg and enjoy city tours with our hand-picked guides. You definitely should experience our river cruise programs.