system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What factors contribute to whether you need to have a/some limbs amputated? Is it damage to bones? Muscles? Nerves?
gpt
Med student here. Most of it has to do with the viability of the limb which is determined by the quality of the blood flow to the limb/extremity.

Muscle, bone and nerve damage are like cutting leaves and flowers off a plant. Blood flow is like removing water. Without consistent flow the thing dies and/or cannot repair.