Internal bleeding should be taken seriously, and not just because it could indicate signs of severe trauma. This form of hemorrhage, which occurs in blood vessels far away from the skin (e.g., between internal organs) can deprive tissues affected of nutrients and oxygen, thus, increasing the risk of adverse events such as ischemia or necrosis. https://www.evolving-science.com/matter-energy/magnetic-nanoparticles-internal-bleeding-00670