Thanks for posting on HCM
From what you have presented your mother might be suffering or suffered from what is usually termed 'dialysis
hangover or dialysis washout' which occurred as a result of side effects caused by removing too much fluid and/or removing fluid too rapidly and presents as low blood pressure, fatigue
, chest pains, leg-cramps, nausea
. The nurse might be right when she told you it was as a result of too much fluid removed. This is a common side effect that occurs as a result of dialysis treatment.
You need to know that even though dialysis is a good way of filtrating waste products from your body, it can not 100% replace the natural functions performed by the kidney
(and since it has failed...) and so comes with many side effects that you can take your time and research on or ask your mother's treating physician for more info regarding side effects of dialysis. Your mother's age might be another predisposing factor to dialysis side effects.
I do not wish that you point any accusing fingers right away to any particular health care practitioner but try to find out more as you are doing right now about the problem.
Hope this helps