Strangely, I agree with your son. Though still undiagnosed after 20 years I have more balance issues when I gain 10lbs so I try to keep down and keep salt intake low. Why no diagnosis you ask, have had more than six diagnoses in past 3 years, but each one taken back. Seems like ligament calcification ES, but doctor said there is no test for ligament. I'm not giving up. Waiting for an ES specialist to accept me as a patient..