How do you correct low sodium in the elderly?

Certainly let them eat as much salt as they need. Restrict liquid intake to max 1.5 litres per day (unless they have a UTI or are constipated: also make sure this is treated!). Have regular blood tests, check kidney functions. My mum is on the mend after mild low sodium knocked her for 6 after several kidney infections, drinking too much water and tea and being on the wrong meds. Avoid meds which cause water retention (ie: some meds for Diabetes II non-insulin users: there are meds which do not cause this). Check the combination of meds with pharmacist and specialists. Find a good geriatrician.