Indigestion, also known as functional dyspepsia, is primarily characterized by symptoms such as abdominal pain, bloating, loss of appetite, nausea, and vomiting, due to impaired food ejection function. Poor appetite can lead to a relative lack of body energy, resulting in symptoms like insomnia, anxiety, and depression. Indigestion is common among children and the elderly or frail. In treatment, it is important to adjust the diet to focus on soft, easy-to-digest foods, eat more fresh green vegetables, and avoid raw, cold, or spicy foods.