Various things can lead to low
blood sugars. If you go without
eating for a period of time, your
blood sugar can
drop, or if you exercise strenuously (especially if you do both in combination). If you are on insulin than taking too much insulin for the carbs you are eating can definitely cause low blood sugars and these can be the more dangerous kind because you can drop very rapidly. If you are getting frequent lows, talk to your doctor.