dehydration: do you know the signs?

have you had a glass of water yet today?

by dave yasvinski

published may 12, 2022

last updated feb 20, 2023

3 minute read

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3 minute read

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dehydration leads to dizziness and low blood pressure, which both contribute to falls. getty

dehydration occurs when the body loses more fluids than it takes in, compromising its ability to carry out important tasks. certain bodily functions, such as sweating, diarrhea or vomiting, can quickly drain the body of fluids and electrolytes that are vital to maintaining good health. water plays an essential role inside the body by circulating nutrients, keeping blood pressure normal, cushioning organs and joints, regulating temperature and preventing heat stroke. because it is possible to suffer the effects of dehydration before experiencing any symptoms, the public health agency of canada recommends drinking fluids prior to feeling thirsty, particularly on hot days.

dehydration takes on added urgency in infants, who are more prone to the condition (through diarrhea, vomiting or fever) and older adults (who naturally have less water in their bodies and may have health conditions that exacerbate risk). mild forms of dehydration can be resolved by consuming fluids but more severe cases usually require immediate treatment.

symptoms of dehydration

the signs of dehydration vary across age groups and can be difficult to detect but common symptoms, according to the mayo clinic, include:

dry lips and mouth
extreme thirst
headache
dizziness and fainting
less frequent urination that is dark yellow and has a strong odour
low blood pressure and increased heart rate
fatigue or confusion

among infants, symptoms include:

dry mouth and tongue
no tears when crying
sunken eyes, cheeks or soft spot on top of skull
no wet diapers for three hours
irritability or restlessness

diagnosing dehydration

a brief inspection of symptoms is usually all a healthcare professional needs to diagnose dehydration, but blood tests and urinalysis can confirm this finding and determine the extent of the condition. children and adults who have experienced extreme dehydration require immediate medical attention and may be given an intravenous mix of salt and fluids to accelerate recovery.

treating dehydration

the only effective treatment for dehydration entails replacing the lost fluids and electrolytes, with the best way to do this varying by age. for infants and children who have become dehydrated through diarrhea or vomiting, over-the-counter oral rehydration solutions are a good option. adults in the same situation should rest and drink plenty of water, avoiding full-strength juices or soft drinks that may worsen diarrhea. if you work outdoors in hot weather, drinking cool water frequently and seeking shade from the sun are effective options.

preventing dehydration

drinking plenty of fluids throughout the day becomes increasingly important as we age. dehydration leads to dizziness and low blood pressure, which both contribute to falls. you should always drink more in hot weather or when active and it is best to skip the soft drinks in favour of water. drinks containing caffeine should be avoided or limited to no more than three per day.

while research has shown it isn’t necessary to drink eight glasses of water per day, it is important to pay attention to signs you may not be getting enough. this includes:

checking your thirst – if your mouth is dry or you feel thirsty, you are already a little dehydrated. try to drink liquids frequently throughout the day
checking your urine – this is the easiest way to determine your hydration level. if your urine is dark yellow and smells bad, you probably aren’t drinking enough water. when you are meeting your hydration needs, your urine will typically be yellow or clear in colour
checking your mood – if you feel lightheaded, tired or are experiencing headaches, you may be dehydrated

support for dehydration

the public health agency of canada has plenty of information explaining the importance of staying hydrated, particularly for older adults. the canadian digestive health foundation is another good resource to help manage your digestive health and ensure you are meeting all of your body’s needs.