STAT means now. Everything else means consult a specialist.
Precision brain surgery using 3D coordinates to target specific areas, like GPS for neurosurgeons except the stakes are infinitely higher than missing your exit. It's the medical technique that allows doctors to insert instruments into your brain with mathematical accuracy, because guessing would be problematic. Also refers to how organisms move when touched, but the surgery definition is way more dramatic.
Medical jargon for 'under the skin,' typically referring to injections that go into your fatty layer rather than muscle or veins. It's where insulin gets injected and where your body stores reserves for the apocalypse. Subcutaneous tissue is basically your meat suit's insulation and padding system.