__________ a medical emergency involving the formation of a clot in a vein deep within the body, most commonly a lower extremity; causes severe pain, redness, significant warmth and swelling of the affected area, engorgement of superficial veins of the affected limb, and can lead to a pulmonary embolism if the clot dislodges and travels to the lung

Fill in the blank with correct word.

deep vein thrombosis