Question from Los Angeles, California, USA:

Last night, after going to bed, a loud sound startled me as I was dosing off. Approximately 15 minutes later, I had a bad hypoglycemic reaction with a blood sugar reading of 34 mg/dl [1.8 mmol/L]. I treated it with a sweet natural snack and blueberries, then went back to bed. I woke with a blood sugar of 240 mg/dl [13.3 mmol/L]. Rather than eat breakfast, I gave myself three units of Humalog. By noon, four hours later, I was back to a blood sugar of 102 mg/dl [5.7 mmol/L]. At lunch, I ate a salad and one dinner roll, and gave myself four units of Humalog. One hour later my blood sugar had shot up to 230 mg/dl [12.8 mmol/L]. First, can getting startled as I did cause a serious hypoglycemic reaction? My night routine was exactly as it normally is. Second, should I expect my sugar readings to bounce around like this after such a low hypoglycemic reaction? For the record, I am very fit at 5’11” 160 pounds. I work out six days a week, eat a fairly low-carbohydrate diet (no junk food) and take 14 units of Lantus and between three and four units of Humalog with each meal. My A1c is 5.4.