SIADH is clinically known as antidiuretic hormone dysregulation syndrome, which means that there are many causes of increased secretion of antidiuretic hormone in the body. When the secretion of antidiuretic hormone is increased, there is a relative lack of urination, water and sodium retention, and dilutional hyponatremia. Patients with dilutional hyponatremia may suffer from weakness and drowsiness, and in severe cases, this may lead to loss of tendon reflexes and coma, which may even be life-threatening. The most common cause of antidiuretic hormone hypersecretion syndrome is malignancy, commonly known as pulmonary oat cell tumor. In addition, antidiuretic hormone dysregulation syndrome can be caused in patients with lung infections as well as those caused by medications. The clinical treatment of antidiuretic hormone disorder syndrome is to use diuretics to increase urination, and mannitol can be used to facilitate the excretion of water.