Chronic diseases are a major cause of death in the world. Thus, many guidelines have been proposed to prevent these diseases. In addition, various systems have been developed to ease health monitoring. However, they are generally behaving as reminders or as anomaly detection systems. After giving an overview of the existed solutions and discussing their drawbacks, the authors present their system which is called ambient healthcare monitoring system (AHMS). It provides a continuous, unobtrusive, and mobile health monitoring of patients with chronic diseases. It is based on the multi-agent paradigm that allows devices to be distributed and autonomous. In addition, it benefits from the characteristics of ambient intelligence (AmI) such as ubiquity and context-awareness. So, AHMS is a promising solution for unobtrusive healthcare monitoring, in which it offers efficient medical services, with less energy consumption, that can significantly reduce the healthcare cost by automating some routine tasks. Consequently, it reduces the latency as well it minimizes the overload on the caregiver.