Historically most nurses were related to war, men fight war and thus become nurses. Even in the modern military you learn how to apply bandages, identify different kinds of wounds and how to treat them etc to keep your mates alive even in the modern military, so you could call everyone in the army a "nurse". But of course they are not modern nurses, the profession changed over time from mostly patching up people after fights to mostly treating diseases as our understanding of diseases improved.

The same thing with programming, women were dominant when it was mostly low level computations, but more and more men joined the field as computers grew more powerful and people saw the breadth of programs you could create. So the job changed, early it was more about maths and algorithms, and then we added more and more engineering tasks on top and people started to create huge programs which doesn't resemble math at all. So the gender balance of programmers shifted from the relatively equal applied math field to the extremely male dominated field of engineering. You can look it up, STEM without E has a very balanced gender ratio, while E tend to have above 80% men.