Elderly Often Have Dehydration Problems

Dehydration in the elderly can be difficult for many doctors to correctly diagnose.

Often doctors become confused because of urinary tract infections (UTIs) and prescribe antibiotics heavily which can then lead to real UTI.

Dehydration means the body doesn’t have as much fluid within the cells and blood vessels as it should. Yes, the body can gain fluid through what we eat and drink. The body loses fluid by urination, sweating, and a host of other bodily functions. When we lose more fluid than we take in, we become dehydrated.

When a person starts to become dehydrated, the body is designed to signal thirst to the brain. Then the kidneys are supposed to start concentrating the urine to lessen the water loss in urine. However, as we age, the body's mechanisms that are meant to protect us from dehydration lose the ability to perform efficiently. The elderly often develop reduced thirst signals and become unable to concentrate their urine.

Other factors that put older adults at risk include:

1. Chronic problems with urinary continence, which can make older adults reluctant to drink a lot of fluids
2. Memory problems, which can cause older adults to forget to drink often, or forget to ask others for something to drink
3. Mobility problems, which can make it harder for older adults to get something to drink
4. Living in nursing homes, because access to fluids often depends on the availability and attentiveness of staff
5. Swallowing difficulties

Dehydration can also be brought on by an acute illness or other event. Vomiting, diarrhea, fever, and infection are all problems that can cause people to lose a lot of fluid and become dehydrated. The elderly are more likely to be taking medications that increase the risk of dehydration, such as diuretic medications, which are often prescribed to treat high blood pressure or heart failure.

In the elderly, the most accurate way to diagnose dehydration is through laboratory testing of the blood. Dehydration generally causes abnormal laboratory results such as:

1. Elevated plasma serum osmolality: this measurement relates to how concentrated certain particles are in the blood plasma
2. Elevated creatinine and blood urea nitrogen: these tests relate to kidney function
3. Electrolyte imbalances, such as abnormal levels of blood sodium
4. Low urine sodium concentration (unless the person is on diuretics)

Doctors often sub-classify dehydration based on whether blood sodium levels are high, normal, or low.

Dehydration can also cause increased concentration of the urine — this is measured as the “specific gravity” on a dipstick urine test. However, this is not an accurate way to test for dehydration in older adults, since we tend to lose the ability to concentrate urine as we get older.

Physical signs of dehydration may include:

• dry mouth and/or dry skin in the armpit
• high heart rate (usually over 100 beats per minute)
• low systolic blood pressure
• dizziness
• weakness
• delirium (new or worse-than-usual confusion)
• sunken eyes
• less frequent urination
• dark-colored urine

But as noted above: the presence or absence of these physical signs are not reliable ways to detect dehydration. The physical symptoms above can easily be caused by health problems other than dehydration.

So if you are concerned about clinically significant dehydration, or about the symptoms above, blood tests results may be needed. A medical evaluation for possible dehydration should also include an interview and a physical examination.

Please read the entire blog here and it explains much more about dehydration.