A 45-year-old woman experienced significant swings in her fasting blood sugar levels, dropping from 216 mg/dL to 87 mg/dL within two days despite consistent diet, routine, and medication. Experts explain that such fluctuations are common in diabetes and can be influenced by various factors including sleep, stress, physical activity, and minor infections. While unsettling, these variations warrant careful interpretation rather than panic, with HbA1c tests offering a broader three-month average.