淤青is the best here for your body's bruise. Never heard about 青瘀。 青肿：青means black and blue, 肿means swelling; be swollen. And for the first answer, 挫伤means contusion. Hope this will be helpful. : )

you may find it in the wikipedia.com

瘀斑 for medical idiom；淤青 for literal idiom;

I really have no idea personally, but below are the definitions and example sentences I found for the dictionary entry for bruise in 牛津现代英汉双解词典. I hope this information will be of some use, but I'm afraid it might only add to the confusion until a native speaker chimes in. BRUISE n injury caused by a blow to the body or to a fruit, discolouring the skin but not breaking it 挫伤: He was covered in bruises after falling off his bicycle. 他从自行车上 下来, 满身青一块、 紫一块. 派生： bruise v 1 [Tn] cause a bruise or bruises on (sth/sb) 使（某物[某人]）受挫伤: He fell and bruised himself/his leg. 他跌倒後身体[腿]受了挫伤. Her face was badly bruised in the crash. 她碰得鼻青脸肿. 2 [I] show the effects of a blow or knock 显出击伤或碰伤: Don't drop the peaches they bruise easily. 桃儿容易碰伤--要轻拿轻放.