Dehydration can be a serious matter with symptoms including lethargy, headache, and even hallucinations. A person may die if the case is extreme.
Elderly people are less likely to be able to tell if they are getting enough to drink and therefore are at greater risk of becoming dehydrated. This is because an area of the elderly person's brain underestimates how much he or she needs to drink.
The part of the brain that indicates to a person how much water she or he needs is called the mid cingulated cortex. In elderly people, this region of the brain malfunctions.
Researchers at the Howerd Florey Institute in Melbourne, Australia studied two groups of people, one group made up of people age 65-74 and the other group of people age 21-30. The participants were given salty water through their vein and then allowed to drink as much water as they wanted. Even though both groups got equally thirsty, the older group drank half as much as the younger group/
Through imaging with a PET scan, the researchers found that the mid cingulated cortex turned off much earlier in the older people than the younger ones. Much smaller amounts of water were needed for the older person's brain to signal "enough".
This is important information for caregivers to keep in mind. Your elderly family member may feel that they have plenty of fluid when they are actually becoming dehydrated. This is especially true in warmer weather.
Remind your loved one to keep drinking those liquids. Adults should drink at least 8 glasses of water per day to prevent dehydration and physically active people may need to drink more.