Two healthcare approaches that seek to customize medical interventions and therapies for specific patients are precision medicine and personalized medicine. These methods are predicated on the notion that each patient’s genetic composition, way of life and surroundings significantly influence their health and reaction to therapy. By examining a patient’s DNA, RNA and protein expression, precision medicine uses genetic and molecular data to pinpoint disease subtypes and provide customized treatments. In contrast, personalized medicine develops a comprehensive treatment plan that is specific to each patient by considering not only genetic information but also other characteristics like the patient’s lifestyle, environment and medical history. Both of these have significant success in the treatment of certain types of cancer (breast and lung cancer), and neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease. Both of these play a significant role in disease treatment but they also have significant effects on early detection and disease prevention. All things considered, personalized and precision medicine are becoming increasingly important in the treatment of diseases. These methods are being utilized to create new medicines for different illnesses and have already resulted in notable advancements in the treatment of several forms of cancer. The purpose of this chapter is to examine the potential, constraints and opportunities of precision or personalized medicine by reviewing current research that places the topic at the centre of the discussion.