The ageing process affects also haematopoiesis and haemostasis and these changes can have a far reaching effect on other organ systems and their function. The authors decided therefore to present a review on involutional changes on the formation and function of blood elements and the system of blood clotting. The review is divided into description of changes in the bone marrow and explanation of hitherto known facts on the pathophysiological background of these changes. Furthermore the authors deal with changes in the peripheral blood stream and their mutual relations with administered drugs, diseases under way, reactions to external stimuli such as immunization etc. In the second part of the review the authors describe changes of haemocoagulation , emphasize the tendency of hypercoagulation and the mutual relationship of the development of atherosclerotic changes and hypercoagulation trends and their pathophysiological background. Attention is paid to thromboembolic disease and its increasing risk in elderly patients incl. the possible late manifestation of congenital defects of coagulation inhibitors. The authors mention also the influence of lifestyle and dietary factors on the coagulation activity in old age. They analyze in detail possibilities and pitfalls of prophylaxis of thromboembolic disease in elderly patients and the risks of haemorrhagic complications of different operations.

        Key words: Haematopoiesis - Haemostasis - Geriatrics - Peripheral blood stream - Haemocoagulation - Hypercoagulation states - Thromboembolic disease