Disease relapse refers to the reoccurrence or worsening of symptoms after a period of improvement or remission. This can happen in various chronic illnesses such as cancer, autoimmune diseases, and mental health conditions. Relapse occurs due to a variety of factors such as genetic predisposition, inadequate treatment, non-compliance with medication, and external triggers. Research in this area focuses on understanding the mechanisms that lead to relapse, developing strategies to prevent relapses, and optimizing treatment plans to reduce the risk of recurrence. By studying disease relapse, researchers aim to improve patient outcomes and quality of life for individuals living with chronic conditions.