Ambient-assisted technologies offer valuable support for persons with special needs, such as older, ill or disabled persons. Relevant support includes assisting in daily life activities, monitoring health conditions, analyzing behavior or affective states and communicating information with caregivers. From a healthcare perspective, these developments are highly valuable and offer new possibilities in the areas of early prediction of diseases and prevention of associated risks. Smart healthcare applications in this context focus on daily activity recognition to provide assistive services for an independent life; on movement tracking and fall detection to prevent accidents and enable interventions; and on physiological health monitoring to assess the vital signals of ill patients and persons at risk. The aim of this paper is to provide an overview on recent activities and advances related to smart healthcare technologies in the context of ambient-assisted living. The paper presents recent studies related to physiological measurements and describes the main requirements and tools needed to realize such systems, including system design, smart sensors, process automation and trust and acceptance aspects. Finally, the paper discusses associated energy challenges and limitations for integrating smart healthcare systems in ambient-assisted environments.