There are two kinds of coverage that can cover if your friends got hurt in your apartment and it depends on how your friends got hurt. If it’s your (the insurer’s) fault, say you forgot to clean the snow on the driveway and your friends slipped and fell, liability can step in to cover the medical cost. If it’s not your fault, say your friend cut his hand when he was helping cooking the dinner, medical expenses can respond to the injury.
The information in this answer is general in nature and is not legal or insurance advice for your specific situation. Policy language varies carrier by carrier; your declarations page is the final word. If you're unsure, call your agent before you need to file.