I won ' t eat this time , but I am worried about my blood sugar dropping too low . My neurologist , who suggested I get my doctor to do the tests , told me to make sure it doesn ' t get too low or I could pass out . I ' ve only passed out once when I was fasting for a blood test . They only checked my vitamin levels that time , since they were doing tests for MS , not a full panel . I get up around 3 am every morning , and my appointment isn ' t until 830 am , so it ' s going to be very hard not to have something , but I must do it . I need to find out what is wrong . Usually when I get up , soon after I start having the effects of low blood sugar , then I either eat an apple , or have some milk . It goes away in few minutes , but it doesn ' t last long and it drops again . I don ' t have a meter to test , but I will ask for a prescription for one so he can see what ' s going on .