Cell injury refers to the damage that occurs to cells due to various harmful factors, such as toxins, lack of oxygen, or infections. This damage can disrupt normal cell functions, leading to cell death or dysfunction. The severity of cell injury can vary, ranging from mild and reversible changes to severe and irreversible damage. When cells are injured, they may undergo processes like necrosis or apoptosis. Necrosis is an uncontrolled form of cell death that often results from acute injury, while apoptosis is a programmed and controlled process that helps eliminate damaged cells. Understanding cell injury is crucial for developing treatments for various diseases.