dysautonomia
"After being a serious athlete my whole life and winning 10 k races last spring,  I suddenly developed autonomic dysfunction (Dysautonomia) about two months ago at age 66.  I am taking 0.1 mg Florinef per day, half before breakfast and half around noon.  I am functioning much better with the medication.  I also drink extra liquid and two 11 oz cans of V8 juice (920 mg Na per can) in morning.  I have been able to continue working full time as a professor, something that I would not have been able to do without the medicine.  Swimming is my only good option for aerobic exercise, so I am doing laps for 30 min 4 or 5 days a week."