What is the term for the formation of a clot in deep tissue?

The term for the formation of a clot in deep tissue is known as deep vein thrombosis (DVT). This condition specifically refers to the development of a blood clot within a deep vein, most commonly in the leg. DVT can lead to significant health issues if the clot dislodges and travels to the lungs, causing a pulmonary embolism.

Understanding why "deep vein thrombosis" is the correct answer involves recognizing that it specifically describes clots that form in deep veins, particularly those in the legs or other deep tissues, as opposed to other types of clot formations. For example, arterial thrombosis occurs in the arteries and can lead to conditions like heart attacks or strokes, which are not related to the formation of clots in deep veins. "Capillary blockage" refers to issues within the smallest blood vessels, which also does not pertain to deep tissue clots. Venous obstruction is a broader term that may imply any blockage in the veins, but it does not specifically indicate the presence of a clot in deep tissues.

Thus, the specificity of "deep vein thrombosis" as the type of clot formation in deep tissues makes this the correct choice.