The rise of deep learning has brought about unparalleled progress in the diagnosis and prognosis of diseases, hence transforming the healthcare industry. This chapter provides a thorough overview of deep learning’s foundational ideas and applicability in the field of medicine. The fundamental ideas of deep learning techniques, such as neural networks and convolutional neural networks (CNNs), are thoroughly examined in this chapter, along with how they are used for the prediction of disease. To give the audience a strong underpinning in the field, the basic ideas of characteristic engineering, data pretreatment, and model evaluation are clarified. The chapter explores a number of practical uses, demonstrating deep learning’s amazing ability to forecast a wide range of illnesses, like cancer, heart conditions, and neurological disorders. It also explores the obstacles and ethical issues surrounding the incorporation of deep learning models into healthcare facilities. Readers will have a thorough concept of the revolutionary role deep learning plays in disease prognosis by the completion of this chapter, enabling them to investigate this emerging topic and positively impact precision medicine and healthcare in the future.