Yes of course it’s a MAYDAY it is a failure of a critical system, AND it is potentially a human life.
You want maximum assistance, MAYDAY comes from the French m’aidez (sp?) = help me. You want to land ASAP, you don’t want ATC to vector you round the houses, or tell you to break off the approach, or go-around, and once on the ground you want to taxi in and get to a gate ASAP, so you can get some medical help.