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.
Typhoid fever facts. 1  Typhoid fever usually is caused by Salmonellae typhi bacteria. 2  Typhoid fever is contracted by the ingestion of contaminated food or water. 3  Diagnosis of typhoid fever is made when the Salmonella bacteria is detected with a stool culture.  Typhoid fever is treated with antibiotics.