This book discusses the influence of the brain microcirculation on the development of the pathological changes in Creutzfeldt-Jakob disease (CJD). Also, the ultrastructural characterisation of pathological aspects of cutaneous microcirculation in patients with vascular cognitive impairments are reviewed. Finally, Non-invasive diagnostic techniques, such as capillaroscopy and nailfold capillaroscopy are examined. The former technique is fundamental in viewing peripheral circulation and in studying microangiopathies. The non-invasive method of videocapillaroscopy is also discussed in relation to how it is used to observe the microcirculation characteristics of the human oral mucosa. Also, Raynaud’s phenomenon, defined as bouts of reversible vasospastic ischemia typically manifested upon exposure to the cold and/or in association with emotional stress, are discussed in relation to nailfold capillaroscopy.