Suggest Remedy For Addisons Disease

My mother is 52 years old and 5 months ago had brain surgery to remove a tumour and during the operation they damaged her pituitary gland so now she has been diagnosed with addisons disease. She is about 5 foot 9 and weighs approx. 80kg and has now been saying she has a salty taste on her lips and feesl it in the back of her throat. Why is this? Does she need more salt or has had too much salt?