During fetal development, the testicles gradually descend from the abdominal cavity into the scrotum. During this process, the descending testicle enters the scrotum along with the two layers of the peritoneum, and the cavity formed between these two layers is the sphincter cavity. Under normal circumstances, the sheath cavity is balanced between exudation and absorption, so that only a small amount of fluid is present. When the sheath itself or an adjacent organ becomes diseased, the balance between exudation and absorption is lost and exudation is greater than absorption.
In addition, the body can suffer from physical and mechanical compression as well as irregular diet, nutritional imbalance and inadequate sleep, all of which can lead to decreased immunity and endocrine imbalance, adding to the burden of the testicular sheath and decreasing its own absorption and sterilisation capacity, thus failing to repair the balance and damage the tissue on its own, all of the above factors can lead to excess fluid in the testicular sheath.