Blood obstruction is a medical condition in which the flow of blood is blocked due to a CLOT or other obstruction. The term 'CLOT' is used to describe the obstruction, and it is a four-letter word. Clots can form in veins or arteries, and they can be caused by a variety of factors, including trauma, infection, or a genetic disorder. Clots can be dangerous if they cause a blockage in an artery, as this can lead to a stroke or heart attack. Treatment for blood obstruction typically involves medications to dissolve the CLOT or surgery to remove it.