Question from New Jersey, USA:

I am a fairly active 18 year old. A couple of days at work, my diabetic friend wanted to see what my blood sugar was so she tested me. The first time and it was 150 mg/dl [8.3 mmol/L] and about a half an hour later it was 170 mg/dl [9.4 mmol/L]. Although I ate a big meal with a 16 ounce cup of soda about and hour before the first testing, I still was suspicious. She tested my other two friends and they were about 90 and 100 mg/dl [5.0 and 5.6 mmol/L], respectively. Is this serious? Should I really be concerned and get blood work done? I read the symptoms and none really match, but some do. For example, I used to get dizzy sometimes, sometimes have fatigue and sometimes have to urinate frequently. I never had a tingly sensation in my fingers or toes nor am I constantly hungry or thirsty nor do my cuts heal slowly. What should I do?