The aim of this paper is to describe an original approach which consists of designing ontology based Medical Decision Support System (MDSS) to enhance the patients' lifestyle. This system is composed of two main parts: data collector which collects relevant lifestyle-related patient data by prompting the only significant questions in connection with the patient's medical background, and advices provider which provides personalized lifestyle advices to the patients regarding their lifestyle changes. The proposed MDSS is integrated within E-care home health monitoring platform in order to: (i) improve the patient's healthy lifestyle; (ii) educate the patients towards their disease; (iii) increase the early detection of risky situation.