Multimorbidity refers to the coexistence of multiple chronic conditions within an individual. This research area focuses on understanding the complex interactions and implications of having multiple chronic illnesses, as opposed to studying individual diseases in isolation. Multimorbidity has become increasingly common due to factors such as aging populations and improved medical care leading to longer life expectancy. Researchers in this field seek to better understand the impact of multimorbidity on patients' health outcomes, quality of care, healthcare utilization, and overall well-being. They also work to develop strategies for managing and treating patients with multiple chronic conditions in a holistic and integrated manner.