Hypoglycaemia means you have low blood sugar. It can occur with the treatment of diabetes. If you have symptoms of hypoglycaemia which aren’t related to diabetes or another serious illness, you can donate as long as you eat a substantial snack two hours before you donate and drink 8 to 10 glass of fluid the day before, then at least three good-sized glasses of water (750ml) in the 3 hours before you donate, and plenty of fluids after.
