What constitutes סכנת אבר and what can you do on shabbat

Question

What damage done to your body would be considered סכנת אבר (sakanat ever, limb at risk), and what Shabbat prohibitions can you break?

This is a NON סכנת נפשות (sakanat nefashot, danger to life) case.

Answer 1

My understanding from Rabbonim today is that anything that is a סכנת אבר is going to lead to surgery, which is going to lead to general anesthetic, which is סכנת נפשות. Certainly as a ספק.

Therefore, today there is no practical distinction.

Answer 2

R Yisroel Pinchos Bodner (Halachos of refuah on Shabbos, p. 113) defines סכנת אבר (limb at risk) as

Any injury or illness that threatens to permanently damage a limb or an external organ, even if his illness does not affect the rest of his body. Even if the injury will cause only partial loss of function of a limb or an organ (e.g., a finger will not be as flexible, an ear will not hear as well as before), it is also included in this category.

Furthermore, any injury or illness which can possibly result in a limb at risk, even if there is only a small chance (sofek) that it will actually happen, is considered a Limb at Risk.

He gives as examples an open fracture or one which would not heal if not treated soon, fractures which might cause internal bleeding, an ear or eye injury.

In this case, one can take medication, ask a non-Jew to do a Torah prohibition and a Jew can perform a drabbanan prohibition even without a shinui (change).

Since these laws are complex, one is well advised to learn them in advance. And of course, consult your rabbi before implementing anything you learn here.