Excess anti-diuretic hormone production and postural hypotension are normal aging changes that make older people more vulnerable to disease and injury. One disease can usually explain most symptoms in an older individual. Most older people have as many as four to six serious and on-going pathological conditions. Restoring or maintaining function is more important in treating older individuals than curing all diseases. Without fever, pneumonia is an unlikely diagnosis in the elderly.
Many older people expect that illness accompanies aging.
The thirst mechanism is unaffected by aging.