Sleep walking is a sleep disorder. People who do this need to see their doctor and get some medication that will keep their brain and body detached during sleep. Our brain and our body is supposed to be detached during REM sleep (when dreaming occurs) for our safety. Sleep walking is a safety concern. The person is acting their dreams out in real life. So, when I'm fighting zombies in my dreams, you don't want me walking around the house near you. Also, people sleep drive, sleep eat (often they are not completely honest about this one), and do many other odd behaviors while sleeping. . They will be seeing things as they are in their dream, not in reality. You could be a zombie, a lover, etc... Who knows what might happen if you try to interact with them.The best things to do for someone who is sleepwalking is to make it so they can't leave the house, hide the car keys, and stay away from them. Get them an appointment with a doctor ASAP for medication or a sleep study to get this sorted out and make it stop happening.
Ive woken up my brother who's sleepwalked to many times to count and he never got hurt hes hurt me though if they go for a car with the keys wake them up people can even sleep drive but usually wreck right off the bat they can also eat,write and anything else that doesnt require vision.