Hypoglycemia is a condition with the blood glucose level below the threshold of 70 mg/dL [1] and is considered serious adverse effect of insulin based treatment for type1 diabetes (T1D) patients. One of the earliest manifestations of hypoglycemia is the involuntary shaking of the human body such as the fingertips.
Paper:
R. McCrimmon, “Glucose Sensing During Hypoglycemia: Lessons From the Lab,” Diabetes Care, vol. 32, no. 8, pp. 1357–1363, Aug. 2009.
American Diabetes Association Workgroup on Hypoglycemia, “Defining and Reporting Hypoglycemia in Diabetes: A report from the American Diabetes Association Workgroup on Hypoglycemia,” Diabetes Care, vol. 28, no. 5, pp. 1245–1249, May 2005.