Dehydration happens when your body loses more fluids than it takes in. Our bodies need water for a variety of processes, including regulating your temperature, getting rid of wastes, and lubricating your joints. 

The general consensus is that an older adult’s water intake should not differ from any other adult’s. We should typically aim for 64 ounces of water daily. The startling reality? Research shows that the average water intake of older adults between the ages of 65-85 is roughly 17 fluid ounces a day and that the average water intake of older adults between the ages of 86-100 is roughly 12 fluid ounces a  day!  

Dehydration is the most common cause of hospitalization in adults over the age of 65. It is so important to stay hydrated. An older adult who is dehydrated may be at a higher risk for complications  like: 

  • Constipation 
  • Electrolyte imbalances 
  • Kidney problems 
  • Loss of balance 

Dehydration risk factors in older adults 

  • A decline in total body fluid. As we age, the amount of fluid in our bodies begins to decrease. This means there are fewer water reserves available for your body to use. ? Lowered thirst response. Feeling thirsty is your body’s way of letting you know you need water. However, because the thirst response becomes weaker with age, older adults may not know they need to drink. 
  • Decreased kidney function. The function of the kidneys can decline with age, meaning that more water may be lost through urination. 
  • Health conditions and medications. Some older adults have underlying health conditions or take medications. In some cases, these conditions or meds can lead to an increase in water loss through urination.

What can cause dehydration? 

Dehydration can have a variety of causes. Below are some of the most common causes of  dehydration in older adults: 

  • Heat exposure. Spending time in hot or humid conditions can lead to increased fluid loss through sweating. 
  • Illness. Being sick with symptoms like fever, vomiting, or diarrhea can cause dehydration quickly. Even common illnesses, such as a cold or a sore throat, may make an older adult less likely to drink enough fluids.  
  • Mobility problems. It may be more difficult for older adults with mobility issues to be able to get water on their own. 
  • Underlying health conditions. Some underlying health conditions, such as diabetes or kidney disease, can cause you to lose more fluid than normal. 
  • Medications. A side effect of some medications may be increased urination, which can cause additional fluid loss. Some examples of medications that can cause increased urination to include diuretics and certain blood pressure medications. Other medications, such as certain cancer medications, may cause increased sweating.  
  • Cognitive Impairment. Older adults who have Alzheimer’s disease or other forms of dementia may need to be reminded to drink fluids or may need help staying hydrated. 

What are the symptoms to look out for? 

Some common signs and symptoms of dehydration include: 

  • dry mouth 
  • tiredness or fatigue 
  • sunken eyes 
  • a decrease in urination – less frequent and/or lower urine output 
  • dark-colored urine 
  • muscle cramping 
  • feeling dizzy or lightheaded 

More serious dehydration symptoms require immediate medical attention. These symptoms include:

  • a rapid heart rate 
  • trouble with movement or walking 
  • confusion or disorientation 
  • fainting 
  • diarrhea or vomiting that lasts longer than 24 hours 
  • urinary and kidney problems, including urinary tract infections, kidney stones, and even kidney  failure 
  • seizures due to low levels of potassium and sodium 
  • pneumonia 
  • heat exhaustion or heatstroke 
  • hypovolemic shock, a life-threatening complication causing a drop in blood pressure and  oxygen levels due to low blood volume 

What are the treatment options? 

Treatment for dehydration involves replacing the fluids that have been lost. For mild to moderate dehydration, this includes drinking water or other fluids, such as juices or broth. Sometimes,  vomiting or diarrhea can lead to a significant loss of electrolytes as well as water. In these situations,  drinking beverages that contain electrolytes may be helpful. Examples include sports drinks and  Pedialyte. If dehydration is more severe, hospitalization may be needed. In this situation, fluids and electrolytes will be given intravenously.

Tips to prevent dehydration 

If you’re an older adult, the following tips may help you stay well hydrated: 

  • Try to drink water throughout the day. Other beverages that may also help with hydration include milk, flavored sparkling water, and fruit juices with low sugar. Drink coffee and tea sparingly, as they can have diuretic effects, meaning more urination and faster dehydration. ? If it’s hard to drink too much liquid all at once, take small sips. 
  • Try to include foods in your diet that have higher water content. Some examples include watermelon, cucumber, celery, strawberries, and low sodium broths or soups. ? If you don’t find water very appealing, try adding a slice or squeeze of lemon or lime to add flavor. There are also sugar-free additives, such as Crystal Light, Mio, Stur, etc. Liquid IV has become a go-to for many older adults as it adds 5x more electrolytes than sports drinks while also adding vitamins.  
  • Plan to drink more water if you’re going to be out in hot or humid conditions for a prolonged period of time, or if you’re going to be exercising. 
  • If you’re ill with symptoms like fever, vomiting, or diarrhea, make sure to drink more fluids than normal. 
  • If you have an underlying health condition, speak with your doctor about your specific fluid and hydration needs. 

If you’re a caregiver for an older adult, you can do the following to help prevent dehydration:

  • Remind them to hydrate throughout the day, especially during mealtimes and after exercise or exertion. 
  • Keep water in places where it’s accessible and easy to reach. 
  • Implement easier access to the bathroom if they’re concerned about not making it to the toilet in time after drinking fluids. 

The bottom line 

Older adults are more susceptible to dehydration. There are many reasons for this, including lower fluid content in the body, decreased thirst response, and medications or underlying health conditions. 

Recognizing the symptoms of dehydration is important so you can work to replace lost fluids. Look out for symptoms like dry mouth, fatigue, dark-colored urine, and lightheadedness. 

Treating dehydration involves replacing lost fluids. You can work to prevent dehydration by making sure you regularly take in fluids throughout the day. This can include water, juices, broths, or foods with high water content. 

If you’re unsure of your hydration needs, talk to your doctor to find out how much water you should be drinking each day. 


Cleveland Clinic. “Drink up: dehydration is an often overlooked health risk for seniors.” 

National Institute on Aging. “Getting Enough Fluids.”

Schols J.M., et al. “Preventing and treating dehydration in the elderly during periods of illness and  warm weather.” The Journal of Nutrition, Health & Aging, 2009: