1 History presents an historian with the task of producing a dialogue between the past and the present. 2  But as these temporal co-ordinates cannot be fixed, history becomes a continuous interaction between the historian and the past.
A routine blood test usually only test for some general features, like potassium, sodium, creatinine, urea, C-reactive protein and a few other. It does often make a blood count of both red blood cells and white blood cells too. In that way it can detect leukemia.
Blood in urine is not always visible. If the amount of blood is small, the urine looks normal. This is called microscopic hematuria because the blood cells are visible only under a microscope. Typically, this is discovered when you have a urine test for some other reason. A trace amount of blood in your urine is normal. The average person with a healthy urinary tract excretes about 1 million red blood cells (RBC) in the urine each day. This amount of blood is not visible. This is not considered hematuria.