Why Do Older Adults Become Dehydrated Quickly?
There are several reasons why dehydration is more common among seniors. Let’s take a closer look at some of them.
A Decline in Total Body Fluid
As we get older, the amount of water our bodies hold begins to decrease. As an older adult, you are more responsible for replenishing your body’s water reserves much more than when you were younger. Everyone loses muscle as we age, and muscle atrophy accelerates as you approach about 70 years old.
Muscles hold the most water, and there are over 600 muscles in the human body! This makes up by far the most weight in humans, so you can see why as we lose muscle we lose water. Also, when partaking in exercise of any form, be sure to hydrate afterwards.
Lowered Thirst Response
It seems intuitive to rely on your body’s natural signals when it comes to your needs. After all, it’s what you have been doing for your whole life. Like we mentioned above, your brain does not work as efficiently as you age, so the signals it sends to let you know you’re thirsty also do not work as well. Thus, you won’t feel like you should drink water even though your body needs it. So even if you don’t feel quite so thirsty, you should have a regular hydration schedule. In other words, reach for that glass of water often!
Decreased Kidney and Brain Function
As you age, your kidneys and brain tend not to work as efficiently as they used to. Your kidneys are responsible for filtering blood and creating water which becomes urine, and your brain is responsible for sending these instructions to your kidneys. Since there is decreased function of both, you have two reasons why you lose more water. First, your brain isn’t telling your kidneys to create the right amount of urine, and then on top of that, your kidneys don’t create the usual correct amount. Unfortunately, this is just part of the aging process.
Underlying Conditions and Medications
Many older adults need to take medications for different conditions as you age. Some common conditions or symptoms that cause direct dehydration are:
- Overheating/heat exhaustion
- Blood Loss
- Increased Urination
Diabetes and hypertension are also common causes of dehydration. With uncontrolled diabetes or high blood sugar, your body attempts to lower the sugar in your blood, and it does this by excreting more water in the form of urine from your body. In addition, you want to make sure that you are on the right dose of diabetes medications – if you force out too much blood sugar through medications, you will also force out water/urine.
Hypertension is another common cause of excessive water secretion. This happens usually after years of uncontrolled hypertension. High blood pressure will eventually hurt kidneys (think of it as pressure from the blood that is directly hitting the kidneys, like chipping away at the blood vessels that course through the kidneys), and if your kidneys don’t work as well, they will produce too much water/urine.
In addition, there are some medications that can cause dehydration, usually through causing increased urination. The most common types of medications that can cause increased urination as a side effect are:
- Diuretics: Heart failure is the most common cause of fluid retention in the body. Your heart doesn’t pump as efficiently, and therefore blood and water get “backed up” into your body and lungs. Diuretic drugs (which many people call “water pills”) such as Lasix and Bumex essentially force you to urinate, and a side effect can be dehydration.
- Anti-hypertensives: These medications dilate your blood vessels; therefore, more blood is filtered through your kidneys causing more urine production and therefore loss of water.
- Drugs for enlarged prostate: Medications such as Finasteride help shrink the prostate. As this happens, more urine is produced, and you can become dehydrated.
- Drugs for anxiety: Medications such as Valium and Xanax work by relaxing your muscles; they also relax the muscles around your bladder, which causes you to urinate more.
In general, everyone should be mindful of their alcohol consumption. Alcohol interrupts the signal between the brain and kidneys that regulates urine production. Because of this, people who are drinking alcohol urinate more than they should.
Bladder infections are a common cause of excessive urination and dehydration. The excessive bacteria and inflammation –– as your body fights the infection –– cause irritation of the bladder itself. This results in bladder spasms, so you will often urinate without meaning to. Additionally, in an effort to fight the infection, your brain tells your bladder to urinate more, essentially trying to “flush out” the bacteria from your body, but this can result in urinating too much, causing dehydration.
Alzheimer’s and Dementia
While not related to the body’s ability to retain fluid, older adults who struggle with memory loss often forget to drink or struggle with the physical act of drinking. This is why, as a caregiver, it is essential to keep track of when a loved one or patient takes in fluids, how much they imbibe, and the specific types of liquids.
A chart, or another written system, can be helpful so that even on the busiest of days, a person with Alzheimer’s or dementia does not begin to suffer from dehydration. The consequences of dehydration for an older adult are much harder to remedy than in younger folk, and indeed, it is easier to simply make sure that an older person’s fluid intake is appropriate, healthy, and nurturing.