The hypothetical creature has evolved on a planet with an atmosphere that's much more pressurised than that of Earth. It's humanoid in appearance, in that it has two arms and two legs as well as a head bearing a mouth and eyes. Its native planet has an atm pressure of, say, approximately three times that of Earth. It usually wears a pressure suit to deal with an atm pressure more akin to what we're used to here on Earth — so if this suit were to be removed or damaged, what would happen to the alien? I'm looking for specific symptoms, here. Describe it as if you were describing what would happen to a human body in the vacuum of space.
Here's some additional anatomical & biological details to help you: It's thin and gangly, with a slim figure and very thin extremities. It stands, on average, slightly smaller than your garden-variety human (5.5 feet, usually). Its bones are quite small and thin, almost like fish bones, and most of them are connected to each other rather loosely. They kind of just 'float around' in the body, supported by the high pressure atmosphere, and are filled with a jelly-like fluid. It has a single lung-like organ — gas is sucked into this organ where it comes into contact with various, inward-pointing 'stems' which have a rich blood supply. It inhales this gas through both its mouth and a secondary hole in its ears, but it has no nose. Its blood is yellow because it contains a lot of sodium. It has four eyes, behind which lie sinuses that are filled with fluid (again, to do with dealing with high pressures). It has a rather thick neck, containing lots and lots of blood vessels and airways, which are both generously coated in rigid chitin to prevent them from collapsing due to the high pressure. Its heart is very thin, but very long, running the length of its torso down to its pelvic region (almost like an insect heart). Needless to say, it has a very high blood pressure. Paradoxically, its native planet has very low gravity, so the pressure suit comes with in-built leg supports to help it deal with a higher gravitational stress than what it's used to.
Thank you! The more detailed and gruesome your answers, the better.