**3. Why is pruritus problematic?**

A recent longitudinal study of CKD-associated pruritus in HD patients have clearly demon‐ strated that significant associations were found among itching intensity, severity, and healthrelated quality of life [HR-QOL] measures in domains such as mood, social relations, and sleep. In Japan, Narita et al. [16] recruited a total of 1773 patients on HD and evaluated the severity of pruritus with a visual analogue scale (VAS). Four hundred and fifty-three patients had severe pruritus with a VAS score of more than or equal to 7.0. Further, 70% of these patients complained of sleep disturbances. From these data, it is clear that patients who suffer from pruritus also have a lower HR-QOL including sleep disturbances which may lead to poor prognosis.
