Primary lymphatic vasodilatation, also known as Waldmann's disease, is a rare disease characterized by increased intestinal protein loss, clinical manifestations of edema, moderate diarrhea, hypoproteinemia, and decreased lymphocytes in the blood. , malabsorption of vitamins & fats and abnormally dilated lymphatic ducts in the small intestine.

Primary intestinal lymphangiectasia (primary lymphangiectasia) was first described by Waldmann et al in 1961 as a rare disorder of intestinal inflammatory disease leading to protein-losing enteropathy (PLE). Primary lymphangiectasia is caused by diffuse or localized dilation and/or rupture of intestinal lymphatic vessels in the mucosa, submucosa, or adnexa due to high pressure within the lymphatic vessels.