Dehydration in older adults symptoms: What are the early signs of dehydration in seniors?

Overview: What does dehydration in the elderly look like?

Dehydration happens when water levels in the body drop below normal. It happens more often in older adults than younger adults for various reasons. The elderly have a lower percentage of water in their body, so they don’t need to lose much water to become dehydrated. The kidneys may not respond fast enough in older people when water levels become low. Age can also affect the thirst mechanism. Humans naturally get thirsty when water levels decrease, but in older adults, this thirst response may become impaired. Older adults are also more prone to medical conditions associated with water loss or more likely to take medications that can cause dehydration. Seniors with incontinence may be worried about drinking fluids. Finally, seniors may be unable to move about or care for themselves, making it difficult to stay adequately hydrated. 

The symptoms of dehydration in older adults are the same as those among younger adults. As with younger adults, older adults may feel thirsty, tired, or cranky when dehydrated. Their lips might get dry, as well as their mouth and skin. Urination decreases, and the urine becomes dark as it becomes more concentrated. People can start getting muscle cramps, headaches, and palpitations as dehydration worsens. They may feel dizzy, lightheaded, and confused. 

What are the early signs of dehydration in older adults?

The early signs of dehydration in seniors typically include:

• Thirst

• Dry lips

• Dry mouth

• Dry skin

• Decreased urine

• Dark urine

• Mood changes

These early symptoms do not always show up as early as they do in younger adults:

• Seniors may have an impaired thirst mechanism. They may not feel thirsty until dehydration is more advanced. 

• The same applies to decreased urination or dark urine. In younger adults, the kidneys quickly sense that water levels are going down, so they adjust rapidly. They filter out less water, so people urinate less, and the urine is more concentrated (darker). In seniors, it may take longer for the kidneys to adjust, so they keep filtering out water as they normally do when water levels are healthy. It may take up to 24 hours after an older adult becomes dehydrated for the kidneys to adjust.

• Skin symptoms are also less evident because of age-related skin changes.

For this reason, it’s important for older adults or their caregivers to monitor their fluid intake and keep older adults hydrated throughout the day before symptoms appear.

Other symptoms of dehydration in seniors

The most common signs of mild to moderate dehydration include:

• Thirst

• Dry lips

• Dry mouth

• Dry skin

• Decreased urination 

• Dark urine

• Headache

• Lightheadedness

• Dizziness

• Loss of coordination

• Tiredness or fatigue

• Impaired cognitive performance (attention, coordination, and short-term memory)

• Mood changes

• Weight loss

• “Sunken eyes” (bags or darker skin beneath the eyes)

Some of these symptoms may be due to loss of electrolytes—particularly sodium—as well as water.

Symptoms of severe dehydration include:

• Extreme thirst

• Fainting

• Muscle cramps

• Heart palpitations

• Orthostatic hypotension

• Altered mental states (such as confusion, disorientation, or hallucinations)

• Increased heart rate

• Rapid breathing

• Unconsciousness

RELATED: Hypernatremia symptoms: what are the early signs of hypernatremia?

Dehydration in seniors vs. dementia symptoms

Even mild dehydration makes it harder to think, concentrate, remember, and perform mental tasks. Severe dehydration may make people confused or disoriented. People can also be more anxious or irritated. All these symptoms can resemble dementia symptoms, such as those in people with Alzheimer’s. There are some critical differences. First, dehydration has other obvious symptoms, like thirst, dry skin and lips, and decreased urination. Second, dementia involves not just cognitive impairment or emotional changes but serious cognitive problems like language and working memory loss, severe psychiatric symptoms, behavior derangements, movement problems, social dysfunction, and sleep problems. Dementia can sometimes affect many functions of the brain. Finally, impairments and mood problems due to dehydration usually improve rapidly when a person gets enough fluids. Dementia doesn’t. Dementia is a progressive disease in which people have good and bad days, but the symptoms gradually worsen.

RELATED: Dementia symptoms: what are the early signs of dementia?

When to see a doctor for symptoms of dehydration in seniors

Except in minor cases, older adults should see a healthcare provider if they notice the symptoms of dehydration or experience dehydration repeatedly. While the symptoms of mild dehydration can be resolved by drinking water, there may be an underlying condition causing dehydration. That condition may need treatment.

Older adults should see a healthcare professional if they’re experiencing dehydration symptoms, frequent urination, vomiting, diarrhea, or any signs of chronic illness like diabetes. Remember, repeated vomiting or diarrhea episodes can easily cause dehydration as well. They should also talk to a healthcare provider if they’re experiencing dehydration while taking medications, especially diuretics (water pills) or laxatives.

Healthcare professionals diagnose dehydration primarily from the symptoms and a physical exam. A recent history will help them identify a cause, such as inadequate water intake, vomiting, or diarrhea. There are no definitive tests for dehydration, but blood and urine tests might help them determine the extent of fluid loss and if there are any electrolyte abnormalities. 

The second stage of diagnosis is to discover a possible cause for the fluid loss, such as an acute or chronic illness, medication use, or problems with kidney function.

Complications of dehydration in older adults

Dehydration is a serious medical condition. Left unresolved, dehydration can lead to severe illness or death. The most common complications of untreated dehydration in seniors include:

• Electrolyte abnormalities, including low sodium (hyponatremia), high sodium (hypernatremia), low potassium (hypokalemia), or high potassium (hyperkalemia)

• Metabolic alkalosis or metabolic acidosis

• Falls and injuries

• Heat exhaustion

• Heatstroke

• Lactic acidosis

• Urinary tract infections (UTIs)

• Kidney stones

• Low blood pressure

• Low blood volume shock (hypovolemic shock) leads to shock liver and liver failure

• Kidney failure

• Death

It is important to note that urinary tract infections can cause mental status changes in older adults as well. If you notice mental status changes or a worsening of dementia, it is important to evaluate the presence of bacteria in addition to the patient’s hydration status.

How to treat symptoms of dehydration in older adults

Dehydration in seniors is treated by hydration and electrolyte replenishment if necessary. Either fluids or fluids with electrolytes are taken orally or administered intravenously. Healthcare professionals take great care when rehydrating older adult patients to avoid complications, particularly those with heart failure or kidney failure. Overly rapid rehydration may cause serious complications, so your doctor will have a plan to do this over a specified period of time. People with low sodium will also require slower rehydration to avoid a rapid and potentially health-threatening rise in sodium levels. If an underlying medical condition is responsible for dehydration symptoms, healthcare professionals will treat that condition separately.

Signs that dehydration in older adults is getting better

The symptoms of dehydration rapidly resolve with rehydration as water and electrolyte levels return to normal. The symptoms of mild dehydration typically resolve in minutes when people start drinking water. Symptoms of severe dehydration may take several hours to get better. 

What’s next? Additional resources for people with dehydration in the elderly symptoms

Test and diagnostics

• Adult dehydration, StatPearls

• Dehydration in the elderly: a short review, Journal of the National Medical Association

Treatments

• Adult dehydration, StatPearls

• Dehydration in the elderly: a short review, Journal of the National Medical Association

• Drink up: the connection between age and dehydration, Cleveland Clinic

Scientific studies and clinical trials

• Cognitive performance and dehydration, Journal of the American College of Nutrition

• Even mild dehydration can alter mood, Uconn Today