Symptoms of mild low blood sugar usually develop when blood glucose falls below 60 to 65 mg/dL and may include:
- Extreme hunger.
- Feeling nervous or jittery.
- Cold, clammy, wet skin; excessive sweating not caused by exercise.
- A rapid heartbeat (tachycardia).
- Numbness or tingling of the fingertips or lips.
If blood sugar continues to fall, the nervous system will be affected. Symptoms usually develop when the blood sugar falls below 50 mg/dL and may include:
- Mood changes, such as irritability, anxiety, restlessness, or anger.
- Confusion, difficulty in thinking, or inability to concentrate.
- Blurred vision, dizziness, or headache.
- Weakness, lack of energy.
- Poor coordination.
- Difficulty walking or talking, such as staggering or slurred speech.
- Fatigue, lethargy, or drowsiness.
(Source: selected from WebMD article)
I've seen some or all of the bolded symptoms when I get very hungry. I get nauseous, nervous, and it's hard to think straight. Sometimes I get a severe headache. When it's particularly bad, I start trembling and get very weak and dizzy.
This explains a lot. I know hypoglycemia runs in the family, and I wondered if I would develop a condition where it would affect me. My mother was affected by nonfasting hypoglycemia, and had some different symptoms (like numbness) - so I was looking for the wrong symptoms, and the wrong circumstances (after eating instead of before).
Now that I know what it is, I feel better. I have a better idea of what to watch out for, and now I know that this seemingly-inherited condition also affects me. I also know that I'm never going to fast on purpose, since these symptoms can easily affect me after only a few hours of not eating (during the day).