Dean- Dean freaks out when you get hurt. Even if its just a little paper cut! He loves you too much to see you hurt and that's why he freaks. However, if you get hurt on a hunt, which he hardly lets you go on, he's quick to react.
Firstly he kills the creature that hurt you and afterwards drops everything, bolting towards you. In these moments all Dean can think about is you and only you. He knows that Sammy can take care of himself. Dean comes over to you, inspecting your body for any serious injuries, even though any injury you get he sees as serious.
He only acts this way because he, as always, blames himself even though you assure him it's not his fault. He's the most sweetest yet overdramatic boyfriend ever and you wouldn't have it any other way.
Sam- Since you're the clumsiest person on Gods earth, you tend to get hurt a lot. That's why you don't go on hunts until absolutely necessary. You like to hang back at the bunker, helping out with the boys dirty laundry and just cleaning. Sounds safe right? Well expect for Deans stinky socks! (Dean: HEY!)
Well somehow even you manage to injure yourself doing that. Toes would be stubbed, you'd slip over and fall on your butt and sometimes even your head would bang against something hard, creating more mess than before. Sam finds it cute but acts like a protective big brother, even though you two are dating!
He would stop what he was doing, when you did get hurt, pick you up bridal style, and rest you on his bed, making sure you were ok. You'd say that you were but he'd still treat you like a princess, bring your favourite foods and just pampering you. He'd even get into bed next to you, cuddling up to you to help take the pain away which was adorable. Sometimes you just acted like you were in pain just to get cuddles from him.
Castiel- When you get hurt, Cas goes emotionless. Like Dean, when he had the Mark of Cain, Cas kills everything in his way, making his way towards you. It quite scary actually, but you know that Cas would never hurt you in million years.
Once he does get to you, he picks you up bridal style, flashes you back to the bunker, puts you in your bed, and heals your wounds. Even though you claim it's just a small scratch, Cas still worries. He's never loved anything as much as he's loved you and it scares him. He doesn't want to lose you.
When he does heal you, he lays with you on your bed. You cuddle up to him and listen to him telling stories about God and other biblical things. You love to listen to his deep voice as you slowly drift off to sleep...
Crowley- When you gets hurt, he gets pissed. Pissed, annoyed, furious, the list is endless. He orders his demons to bring you into his chambers and put you on the bed. Once they do that, Crowley kills them for not protecting the Queen of Hell. Afterwards, he turns to you, assessing your wounds. He utters his favourite quote; "bollocks!"
He feels worthless that he couldn't protect you, even if he was the King of Hell. His voice booms for a doctor and almost immediately one stumbles in. When the doctor heals your wounds, he scurries out. Crowley, sits by your bed, holding your hand, like he was afraid you were going to die. He doesn't leave that spot until you are well again.