Especially if this blood vessel was in your lungs, a pulmonary embolism, and you blocked the blood flow entirely to be able to get oxygenated, you're in big trouble.
If a pulmonary embolism occurs, it can cause sudden shortness of breath and chest pain, and depending on the amount of lung tissue affected, it can even be fatal.
This can trigger body-wide inflammation and blood clots— which can in turn cause heart attacks, pulmonary embolisms, strokes and even damage to tiny blood vessels in the fingers and toes.