Thirty hospitalized diabetics completed symptom checklists immediately prior to monitoring their own blood glucose level seven times a day for 6—10 days. For each subject, simple correlations were computed between each of the physical symptoms and blood glucose level. Most subjects evidenced several symptoms that were highly correlated with glucose fluctuations. Further, the symptoms that were related to glucose differed from subject to subject. The symptom-glucose correlations were reliable and unrelated to sex, age, duration of diabetes, and other individual difference variables. The findings point to a technique wherein patients can learn to perceive physical sensations indicative of changes in blood glucose in natural settings.