1 Blood clots can also obstruct veins, causing pain. 2  Veins return blood from the legs to the heart. 3  There are two systems of veins in the leg: superficial and deep. 4  If a blood clot occurs in a deep vein (deep venous thrombosis), it causes a damming effect, and blood is trapped behind the blockage.
Typhoid fever, also known simply as typhoid, is a symptomatic bacterial infection due to Salmonella typhi. Symptoms may vary from mild to severe and usually begin six to thirty days after exposure.
Paratyphoid fever is an infection which is similar but has milder symptoms. This is caused by the bacterium Salmonella paratyphi. There are three strains of Salmonella paratyphoid: often called strains A B and C. A is the most common worldwide, although B is more common in Europe. C is rare.he diseases are known by various other names, such as gastric fever, enteric fever, abdominal typhus, infantile remittent fever, slow fever, nervous fever, and pythogenic fever. The name typhoid means resembling typhus.