I used to own a mare (just sold her actually) who would rear a lot. She was checked for pain and discomfort several times and that simply wasn't the cause. Bailey is an alpha mare. She just didn't wanna do whatever she was asked and woul start rearing. I'm a nervous rider, but I didn't give up. In Clinton's vid Eternal posted, he shows the leg yielding exercise. You could feel when Bailey was going to rear so I'd just do that to her to prevent it. The thing with rearers is if they get the chance to stop or slow down, up they go. It's all about keeping the horse moving forward and actively.
I was told to crack Bailey over the head with an egg. What a ridiculous thought, you say the rearing's dangerous, why on earth would you want to panic a horse any further... I can only see that being more fault for disaster, as a horse panicking is not something I'd like to be on. In fact, I just broke my leg, because my incredibly quiet horse went into panic mode. I certainly wouldn't want to smack Bailey over the head and have her bolt off on me.
I sold her to a family who have two little girls to ride her. They're having no problems with her rearing because they followed along with keeping her feet moving and have done a lot more ground work with her, and have more control over her feet.
If you feel inexperienced to deal with the rears, I would get experienced help. But it's not something that you cannot attempt to fix. Anything with horses can be dangerous. It's the risk we take every time we get up in the saddle.
♥ Seoul Searchin' for the Lovebug ♥