[Significance of the so-called symptomless periods of disease]

Considerable change has occurred to nosology due to the advent of electron microscopy and its use in investigations of pathological processes. These investigations have shown that morphological alterations under the impact of pathogenic factors may persist for extended periods of time without any clinical manifestation due to soon effectiveness of mechanisms of compensation in the form of regeneration and hyperplasia of cells and intracellular ultrastructures (intracellular regeneration). Clinical symptoms will not grow manifest until regeneration and hyperplasia are not capable any more of compensation for tissue lesions that have resulted from dystrophy and necrosis. This is likely to offer an explanation for delay of treatment, when a patient will not see a physician until the disease has become incurable. It is the established purpose of early diagnosis to detect structural alterations in organs during the asymptomatic preclinical period, that is before the disease has reached an advanced stage. The idea of "primary existent functional and secondarily added morphological alterations" is just as erroneous as that of the existence of "purely functional diseases". Such outdated concepts used to be based on underestimation of compensatory reactions of the organism and the enormous role played by them in the development and outcome of pathological processes.