I'm not entirely sure if this is Internal Medicine or not, but I don't think it's Fitness and Nutrition.

Yesterday I was at work, I'd been there for about an hour when I was walking along and carrying something (I stock at a grocery store) and I broke out in a cold sweat, my skin sort of felt buzzy, and my hands were shaking really bad.

Now this has happened before. About a month ago my knees were really hurting me, I think, just from the drastic change of not bending my knees so much and then doing it every 45 seconds. So everytime I'd bend my knees(crouch towards to the ground, to be specific) I'd feel pain, and the cold sweat thing and shaking hands would happen again.
When it's happened before, I just work it off. I can't really go sit down for no reason, I'm not being paid to do that. So I just ignore and keep doing what I'm doing. Yesterday, I said Screw it I'm going to go get something to drink.
I got some change from a girl up front who I remember telling me a while ago that she had to drop her classes because she kept having unexplained fainting spells. I forgot this until I conversationally said, 'I feel terrible, my hands..." Then she tells me that happens to her before she passes out, and something about my blood sugar being low.

Now the whole situation worries me because I don't have any clue as to why this is happening to me. It happens about once every two weeks, and I only work two days a week now, because of school. My grandfather was diabetic, but I don't think I am. And yesterday I don't understand how my blood sugar was low because I had blooming Cocoa pebbles for breakfast! I just need some ideas of what is causing these. They make me feel crappy, and I don't like them. I'd rather pass out than feel like I'm going to pass out for a prolonged period of time.
Any ideas?

Could be your sugar level, could be a couple things. Do you exert yourself so much and then that is the time it does it, or does it happen at variable times of the day?
In the morning, I get this feeling all the time from not eating and just having coffee for breakfast (bad habit). The only thing that remedies this is grabbing some cheese crackers with peanut butter, or something like that. You may want to get a blood test taken, just to be on the safe side, especially since it runs in the family. Hopefully, you just need to take care of yourself, which includes plenty of rest and eating properly, that means not just junk food....veggies and fruit! I know...I should practice what I preach, Lol.
Good Luck with this, let us know what you find out.

Since you had some Coco Pebbles for breakfast you probably got a sugar rush from it, felt fine and then just "crashed". Try skipping the sugar cereals and eat something nutritious for breakfast. Loading yourself up with a bowl of sugar will leave you without enough energy to make it through your day. When you felt sick and got something to drink, was it more sugar? Did you grab a Coke thinking your sugar level was low? Instead of reaching for a vending drink, carry a bottle of water with you. When you reach for the vending machine is it for a candy bar or a quick fix? Cut out most of the sweets and go for more nutrition. It sounds like you are just so hungry (famished) by mid day you get shaky and start feeling sick. Make an appointment with your doctor and get the blood work that soaringhorse suggested. Good Luck to You.

Stress could also mess with your blood sugar. It doesn't mean you are diabetic. When I was in nursing school, I had spells quite similar to what you are experiencing, and once I got done with school I was fine.

There are other things that could be causing these spells, but sugar sounds like the most likely.

Go to the doctor.

Hypoglycemia comes to mind. Before you rush off to the doctor for pills, or in concern a hypoglycemic reaction can happen to anyone and does not immediate mean you have diabetes or a sugar issue other than poor diet. Coco Pebbles do not a terrific breakfast make – unless you are 6 years old, of course.

Next time it happens pop a candy, say a candy bar, followed by a carb and a protein. A peanut butter sandwich is a perfect carb & protein mixture. The sugary candy bar will dump sugar into your system immediately, the protein and carb will slowly add sugar to your blood stream to keep the amount steady.

Sugar is energy, if you are working harder than before you are burning more energy, thus you may need more carbs in your diet to give you energy through out the day. Sugar (refined) by itself is not a good carb, you need something like a starch (rice, potatoe, bread) that will convert slowly to sugar.

I would suggest a more rounded breakfast, say juice, coffee (if you drink it) and something other than sugar stuffed, frosted cereals. An egg sandwich perhaps, toast and a small amount of jam, there are no breakfast pockets which are better for you than sugar coated, sugar flakes.

I would also suggest that you eat a snack – a good snack, even a piece of fruit – between breakfast and lunch. A lack of food means a lack of energy which can cause a sugar crash. Drink more clear liquids; say iced herbal tea with a minimal amount of sugar in it, or water. Soda is bad, very bad for a worker, it can cause minor dehydration, most contain sugar which stress the body by giving a sugar rush followed by a sugar crash, and contain caffeine which acts much like sugar.

My mother and I get the same thing sometimes. We contacted a nurse about it and they said it was low blood sugar too. They said right as you get up from bed to eat a banana and an orange juice before you get up. For some reason, those two things really help. I hope everything gets better.
Ca33

You should see a dietician to get recommendations to regulate your diet to avoid these situations. Advising to eat a banana is fine, but there are ways to keep from having low blood sugar in the first place by having a good diet for your physical makeup.