Since the 1970s, the usefulness of nailfold capillaroscopy (NFC) in the diagnosis of rheumatological disorders such as systemic sclerosis has been well known, and further studies also showed that NFC can detect non-rheumatic diseases such as diabetes, glaucoma, dermatitis, Alzheimer disease, and so on. In the past decade, the morphological changes in the nailfold capillary have been also reported in the unhealthy lifestyle habits such as smoking, inappropriate diets, sleep shortage, and even psychological stress which presents slow blood flow. Therefore, study in the relationships between the morphology of nailfold capillaries and lifestyle habits has high potential to understand the unhealthy state, or even predict the pre-disease condition. So, simple, inexpensive, and non-invasive methods such as NFC are constantly needed for routine health checkups. Thus, we undertook a systematic search in PubMed database, and summarized the studies reporting the assessment of morphological NFC in order to undertake a comprehensive review on the usefulness of NFC not only in clinical diagnosis, but also in unhealthy dietary lifestyle improvements. Here in this review paper, we finally summarized the dietary and lifestyle health promotion strategy judging from NFC- and the other relating-measurement from the viewpoint of healthy microvascular blood flow and endothelial function.