As a result, a glaring deficiency in the Transcutaneous oxygen saturation of scalp tissue arises in the affected areas of the scalp. Measurements revealed a local oxygen reduction by approximately 40%. A significant lack of oxygen not only in tissues, but especially at the hair roots embedded exists so. This lack of oxygen has fatal consequences. The healthy growth of hair directly depends on a sufficient or at least sufficient blood, oxygen and nutrient supply to the hair follicles from the subcutaneous blood flow in the scalp area is therefore normally around 10 times higher than the subcutaneous blood flow in other areas of the body one of the first clinical signs of reduced peripheral blood flow is typically hair loss. The hair matrix cells, that produce keratin, have about 8 times higher to produce hair daily 1/3 mm Cell division activity than normal skin cells. They are therefore extremely vulnerable to fluctuations in their local metabolic quality, so in particular the undersupply with oxygen.

The biological processes in the hair matrix cells need this oxygen deficiency typically below the critical limit of 40 mmHG expire (oxygen partial pressure measured in mm of mercury). As a result, The hair roots verhornen specifically in these affected regions with the androgenic hormone DHT (dihydrotestosterone). Shrink the roots, the hair follicle degenerate. Shorten the anagen phase of the hairs, the telogen phase stretches (over multiple cycles). The transition in the anagen phase no longer takes place. The hair remains down.

The typical voltage hair loss (alopecia Contentionalis) starts on the forehead, temples or the tonsure. The scalp tension is often much higher in these areas of the scalp. Slightly slower hair loss over the skull roof evolved, there are the blood and oxygen supply less severely affected. In old age, the hair is retained in a wreath of hair around the back of the head (donor area) supplied with sufficient blood and oxygen.