I've had this sort of thing from the other side (female engineer). Don't judge the whole industry on one workplace. Gender balance and attitudes vary massively with different workplace cultures. You'll also find that cultures change over time. Being the only one is hard (I'm the only woman in my group of over 20 at the moment) but as people get to know you, you will be judged on your performance more than your gender, if you take opportunities to show you can do the work you will win peoples' trust.
The biggest thing for me is having a boss that supports you being there, if you have that, the rest of the team will usually follow.
Also, like Mr Dorothy, I've known a few male nurses, and they are generally respected and treated well. Yes, it is usually them that are called if a patient is aggressive or something heavy needs to be lifted, but if you can handle that, it can be a great career for men.