<s>[INST] I have a friend who recently is having dizzy spells. We have sort of figured if he ate to much sugar then stand up he gets dizzy. This does not happen all the time. He does have a drain tube in for gall bladder that is to be removed. Could this be causing the problem? [/INST] Hi, Thanks for your question. After going through your question, there are following possibilities for your friends symptoms-1) Reactive hypoglycemia - this is due to sudden release of insulin after sugar intake which lead to low blood sugar level (hypoglycemia) which can be confirmed by doing blood sugar level during episode of dizziness.2) Postural Hypotension - fall in blood pressure after standing from lying down or sitting position. Which can be confirmed by checking blood pressure in lying down and standing position.3) Other rare possible causes may be - - Syncope.  - Deny Chat Doctor.  - Inadequate nutrition. It may not be related to his gall bladder  </s>