All abdominal compression syndromes are caused by an exaggerated lordosis with a significant reduction of the intra-abdominal space and a compression of structures which cross the spine - veins and parts of the gastrointestinal tract. Thus, all intra-abdominal and many extra-abdominal vascular compression syndromes are part of a single entity - the midline congestion syndrome. Since many midline structures are involved (inner and outer genitals as prostate, uterus, vagina and penis, rectum, urethra, urinary bladder spinal canal, skull, coeliac plexus, duodenum, stomach) the patients present a pittoresque symptomatology and medical history. The potpourri of symptoms can only be explained with the knowledge of the underlying pathophysiology. Unfortunately, still most of the patients are diagnosed as psychosomatic disorders obstructing a proper causal vascular surgical treatment. The increased lordosis is found mainly in women, predominantly with connective-tissue disorders (Ehlers-Danlos syndrome for example). The diagnostics rests on 3 pillars: Clinical symptoms, morphology and function. The quantitative functional colour Doppler sonography is an indispensable means to therapeutic decision making. It defines the localization of the vascular compression, its impact onto the intravascular pressure, the volume and direction of collateral flow, capacity of the collateral route and describes numerically the effect of everyday situations (uptake of food, change of body posture, exercises, micturition etc.) onto these parameters and simultaneously onto the clinical presentation. A successful treatment requires the detection or exclusion of all possible compression syndromes with left renal vein and left common iliac vein compression being the most frequent ones.