Dehydration in adults overviewDehydration is a condition that occurs when the loss of body fluids, mostly water, exceeds the amount that is taken in. With dehydration, more water is moving out of our cells and then out of our bodies than the amount of water we take in through drinking.
We lose water every day in the form of water vapour in the breath we exhale and as water in our sweat, urine, and stool. Along with the water, small amounts of salts are also lost.
When we lose too much water, our bodies may become out of balance or dehydrated. Severe dehydration can lead to death.
Causes of dehydration in adultsMany conditions may cause rapid and continued fluid losses and lead to dehydration:
- High temperature, heat exposure, and too much exercise
- Vomiting, diarrhoea, and increased urination due to infection
- Diseases such as diabetes
- The inability to seek appropriate water and food (an infant or disabled person, for example)
- An impaired ability to drink (someone in a coma or on a respirator, or a sick infant who cannot suck on a bottle are common examples)
- No access to safe drinking water
- Significant injuries to skin, such as burns or mouth sores, or severe skin diseases or infections (water is lost through the damaged skin)
Symptoms of dehydration in adultsThe signs and symptoms of dehydration range from minor to severe.
- Increased thirst
- Dry mouth
- Palpitations (feeling that the heart is jumping or pounding)
- Sluggishness, even fainting
- Inability to sweat
- Decreased urine output: urine colour may indicate dehydration. If urine is concentrated and deeply yellow or amber, you may be dehydrated.
When to seek medical careSeek medical advice if the person experiences any of the following:
- Increased or constant vomiting for more than a day
- Temperature over 38C (101F) that doesn't settle with temperature-lowering measures and medication
- Diarrhoea for more than two days
- Weight loss
- Decreased urine production
- Temperature higher than 39C (103F) that doesn't settle with temperature-lowering measures and medication
- Difficulty breathing
- Chest or abdominal pains
- No urine in the last 12 hours
Examinations and testsThe doctor may perform a variety of simple tests at the examination or send blood or urine samples to the laboratory. Through tests and examination, the doctor will try to identify the underlying cause or causes that led to the dehydration:
- High temperature, increased heart rate, decreased blood pressure, and faster breathing are signs of potential dehydration and other illnesses.
- Taking the pulse and blood pressure while the person is lying down and then after standing up for one minute can help determine the degree of dehydration. Normally, when you have been lying down and then stand up, there is a small drop in blood pressure for a few seconds. The heart rate speeds up, and blood pressure goes back to normal. However, when there is not enough fluid in the blood because of dehydration and the heart rate speeds up, not enough blood is getting to the brain. The brain senses this condition. The heart beats faster, and if you are dehydrated, you feel dizzy and faint after standing up.
- The colour and clarity of urine, the urine specific gravity (the mass of urine is compared with equal amounts of distilled water), and the presence of ketones (carbon compounds - a sign the body is dehydrated) in the urine may all help to indicate the degree of dehydration.
- Increased glucose in the urine may lead to a diagnosis of diabetes or indicate loss of diabetic control and a cause for the dehydration.
- Excessive protein may signal kidney problems.
- Signs of infections or other diseases, such as liver disease, may be found.
- The amount of salts (sodium and potassium) and sugar as well as indicators of kidney function (U+Es and creatinine) may be important to evaluate the degree of dehydration and possible causes.
- A full blood count (FBC) may be ordered if the doctor thinks an underlying infection is causing the dehydration. Other blood tests, such as liver function tests, may be necessary to find causes of the symptoms.
Dehydration in adults - self-care at homeTry to get people who are dehydrated (even those who have been vomiting) to take in fluids in the following ways:
- Sip small amounts of water.
- Drink carbohydrate/electrolyte-containing drinks. Good choices are sports drinks or prepared replacement solutions.
- Suck on ice lollies made from juices and sports drinks.
- Suck on ice chips.
- Sip through a straw (works well for someone who has had jaw surgery or has mouth sores).
- Remove any excess clothing and loosen other clothing.
- Air-conditioned areas are best for helping return body temperatures to normal and break the heat exposure cycle.
- If air conditioning is not available, increase cooling through evaporation by placing the person near fans or in the shade, if outside. Place a wet towel around the person.
- If available, use a spray bottle or misters to spray luke warm water on exposed skin surfaces to help with cooling by evaporation.
- Avoid exposing skin to excessive cold, such as ice packs or ice water. This can cause the blood vessels in the skin to constrict and will decrease rather than increase heat loss. Exposure to excessive cold can also cause shivering, which will increase body temperature. This is the opposite effect you're trying to achieve.
Medical treatmentTreatment in accident and emergency centres first on restoring blood volume and then body fluids, while determining the cause of the dehydration.
If your core body temperature is greater than 40C (104F), doctors will cool the entire body. They may promote cooling by evaporation with mists and fans or cooling blankets and baths.
- If there is no nausea and vomiting, fluid replacement begins. You are asked to drink electrolyte/carbohydrate-containing fluids along with water.
- If there are signs of significant dehydration (elevated resting heart rate, low blood pressure), fluids are generally given through an IV.
- If your condition improves in accident and emergency, you may be sent home, preferably in the care of friends or family.
- If you remain dehydrated, confused, feverish, have persistently abnormal vital signs, or signs of infection, you may need to stay in the hospital for additional treatment.
MedicationsIf high temperature is a cause of dehydration, the use of paracetamol or ibuprofen may be used. This can be given by mouth if you are not vomiting.
Next stepsCall or return to your doctor or the hospital as instructed.
- Take prescribed medications as directed.
- Continue to keep yourself well hydrated with plenty of water or sports drinks.
- Watch for signs of dehydration in yourself and others.
PreventionThe foremost treatment for dehydration is prevention. Anticipate the need for increased fluid intake.
- Plan ahead and take extra water to all outdoor events and work where increased sweating, activity, and heat stress will increase fluid losses. Encourage athletes and outdoor workers to replace fluids at a rate that equals the loss.
- Avoid exercise and exposure during high heat index days. Listen to weather forecasts for high heat stress days, and plan events that must occur outside during times when temperatures are cooler.
- Ensure that older people, infants and children have adequate drinking water or fluids available and assist them as necessary. Make sure that any incapacitated or impaired person is encouraged to drink and given adequate fluids.
- Avoid alcohol consumption, especially when it is very hot, because alcohol increases water loss and impairs your ability to sense early signs associated with dehydration.
- Wear light-coloured and loose-fitting clothing if you must be outdoors when it is hot outside. Carry a personal fan or mister to cool yourself.
- Break up your exposure to hot temperatures. Find air-conditioned or shady areas and allow yourself to cool between exposures. Taking someone into a cooled area for even a couple of hours each day will help prevent the cumulative effects of high heat exposure.
OutlookWhen dehydration is treated and the underlying cause identified, you will recover normally. Dehydration caused by heat exposure, too much exercise, or decreased water intake is generally easy to manage, and the outcome is excellent.