The development and use of electronic health records (EHR) have had remarkable impacts on human life, such as improvements in the quality of medical care, better research results, and enhancements in treatment methods. Despite these improvements, availability, security and privacy concerns have remained to be very important in this field. In this article, we propose a decentralized and distributed system for electronic health records management with the help of the blockchain technology and its potential benefits. In this system, patient information is stored in the cloud. Also, the real owner of the electronic records is the patient, and with the help of smart contracts and encryption, he/she controls how to access his/her health information. In the proposed solution, the problem of sharing and storing the patients’ keys has been solved with the help of smart contracts. In addition, we proposed solutions to special cases which are raised by transferring the control of the records to the patients such as permissions for underage patients, in emergency situations, and after the death of the patient. Comparison of the related works shows that the proposed system has solved the problems of competing systems while maintaining a high level of privacy.