Chronic diseases are also called as non-communicable diseases, which generally can be seen in older adults. These diseases will generally stay for one year and more and limit the daily activities of patients. They need continues monitoring. According to WHO most affected people are from low and middle-income countries. People with low educational background and poor life styles are mostly affected with chronic diseases. These diseases are causing 41 million of deaths each year, which is 74% of total global deaths. These diseases are posing huge budget on the governments for preventing, diagnosing, controlling, and providing medications to the patients. These diseases need to be detected and treated as soon as possible to prevent huge losses. In this article we have studied how semantic web technologies can be used in diagnosing these diseases. We have also proposed a novel method using semantic web technologies for efficiently diagnosing the chronic diseases.