Hi, Thank you for posting your question here, I will try to answer it to the best of my abilities. Well the simple diagnosis would be that you suffered from hypoglycemia at those moments, so try not to skip any meals. Another common cause could be that you have anemia, when was the last time you had your blood work checked? If it was a long time ago, I recommend you see a doctor and have yourself checked for anemia. I hope this answered your question.