Ulm, Germany - An 18-year-old sleepwalker who climbed out his own bedroom window while asleep has died of his injuries after falling seven storeys, German police said Wednesday.

His family, who had worried for years about his disorder, called emergency services at 5 am (0400 GMT) Tuesday to their apartment block in the southern German city of Ulm after finding the youth seriously injured on the ground.

Police said he seemed to have opened the seventh-storey window and simply stepped over the edge. He died in hospital Tuesday evening.

Sleepwalking or somnambulism is a condition where people, most often children and teenagers, leave their beds and move around with their eyes open while in a sleep-like state. (dpa)