1 A blood clot that forms inside one of your veins or arteries is called a thrombus. A thrombus may also form in your heart.  A thrombus that breaks loose and travels from one location in the body to another is called an embolus.
The kidneys. The kidneys do vital work in the body filtering blood removing waste into urine, and balancing electrolyte levels. Our blood in our bodies passes through the kidneys several times a day. The kidneys are located at the back of the abdomen. Each kidney is about the size of a fist - 10-12.5cm long.
The kidneys are two bean-shaped organs (actually resembling kidney beans) that are located in the middle of the back, with one on each side of the spine. Envision two fist-sized organs lying just beneath the rib cage but toward the back, with other organs such as the stomach, liver and large intestine in front of them.