Diseases such as diabetes are known to reduce blood circulation in the capillaries and arterioles; however, there are no devices that can easily measure this on a daily basis. In this study, we developed a tool for measuring finger photoplethysmograms using green-light and near-infrared LEDs. We then conducted photoplethysmography on 25 diabetic inpatients/outpatients as well as 21 adult males and females who had not been diagnosed or treated for diabetes, hypertension, or cardiovascular disease (as a control group). In the diabetic patients, the inverse full width at half maximum velocity plethysmogram (1/FWHMVPG) tended to be smaller compared to the control group, and the delay in the green light a-wave peak relative to the near-infrared light a-wave peak in the acceleration plethysmogram was significantly increased. The results suggest that peripheral hemodynamics could be easily estimated at home using a photoplethysmography device mounted on a ring-wearable device.