Inside the body, the diaphragm is a membranous layer of muscular tissue between the thoracic and abdominal cavities, located below the heart and lungs and above the abdominal organs such as the liver, stomach, spleen, and intestines. The diaphragm is tightly connected to the peritoneum and pleura, with the pleura attached to the abdominal cavity and the peritoneum pressed against the surface of the abdominal cavity. The three are connected around each other, and the heart and lungs exist in the space formed with the thoracic cavity, and organs such as the stomach and intestines, spleen, kidneys, and pancreas in the space formed by connection with the peritoneum. The diaphragm, which fills the lungs with gas as it expands downward, is an important muscle for abdominal breathing and plays a vital role in respiratory movements. If the diaphragm is broken, the patient will be unable to breathe and suffocation will occur. The diaphragm also plays a role in maintaining stable intra-abdominal pressure, creating a favorable environment for the functioning of the body’s organs, such as during vomiting or defecation, by increasing or decreasing intra-abdominal pressure through the movement of the diaphragm, which can promote gastrointestinal motility. The diaphragm can also play a role in stabilizing and promoting the breath, which can be fully utilized when learning to sing. In addition, the hiccups that often occur in daily life are in fact mainly due to spasms of the diaphragm, mostly caused by eating too fast or eating food that is too cold, etc. They usually recover after a period of deep breathing and rest.