No-one knows absolutely why sleep walking occurs. It can be genetic and it can be aggravated by tiredness, stress, alcohol, drugs, illness or medication.
The activities that people are capable of while not fully awake are incredible and include walking, domestic tasks, eating and even driving!
Sleep apnoea and restless leg syndrome can both be triggers to sleepwalking so addressing the symptoms of these issues can help.
One of the most useful interventions is ensuring a clear and effective pre-sleep routine to prepare the body and mind for a restful night and make sure you can calm your mind and relax your body as thoroughly as possible.
Managing fluid intake is also important as the need to use the toilet can trigger sudden wakefulness resulting in sleepwalking.
It's also worth looking at how you run your day to make sure there are breaks to deal with your busy routine as you go along. If you avoid this and try to process everything that's happened during the day late at night this process may leak into your sleeping hours.