Will a broken blood vessel in the neck heal on its own?

Usually 7 to 10 days. If a vein is bruised this usually results in bleeding either under the skin to form a hematoma (trapped clotted blood) or from the skin directly. Veins injured below the skin with a hematoma will take about 7 to 10 days to heal while a vein bleeding from the skin will usually stop with direct pressure and heal within 5 to 7 days.