Hemodialysis (HD) is a clinical treatment that requires the puncturing of the body surface. However, needle dislodgement can cause a high risk of blood leakage and can be fatal to patients. In addition to, some patients with autonomic neuropathy, diabetes or cardiac disorder may have certain symptom which called 'Cold Sweating' during hemodialysis treatment. It is also an abnormal condition that needs to be monitored. This study proposed a novel wearable device for blood leakage monitoring during HD using an array sensing patch, wide range of impedance measure and frequency span. It could distinguish the difference between blood leakage and sweat at the same time, it will provide better mechanisms for monitoring clinical care. Subsequently, the array sensing patch combined with a mapping circuit and a wireless module could measure and transmit risk levels. The different risk levels could improve the working process of healthcare workers, and enhance their work efficiency and reduce inconvenience due to false alarms.