Dehydration is a lack of water in the body, which disturbs the careful balance of minerals. This can be caused by many things, such as not drinking enough water, sweating, vomiting or diarrhoea.

Left unchecked, dehydration can be serious so it’s important you know the symptoms and signs so you can take action quickly.

What are the most common symptoms of dehydration?

The most common signs that you could be suffering from dehydration are:

  1. Thirst (a dry or sticky mouth). This may seem obvious, but when you’re thirsty, it’s a sign that you’re already starting to dehydrate
  2. Not urinating much or darker yellow urine
  3. Dry, cool, shriveled skin, or sunken eyes
  4. Headache
  5. Tiredness, irritability or confusion
  6. Dizziness or light-headedness
  7. Rapid heartbeat and/or breathing.

What causes dehydration?

Dehydration is often caused by simply not drinking enough water, sweating, vomiting or diarrhoea.

Certain people are more vulnerable to dehydration, and a number of factors contribute towards this, including:

  • Body size
    Children and infants are more prone to dehydration.
  • Age
    As you get older your body isn’t as efficient at conserving water and responding to changes in temperature. You also become less aware of thirst. Elderly people may simply forget to eat or drink entirely and may need to be reminded.
  • Medications
    Certain medications, such as diuretics and some blood pressure medicines, can increase your risk of dehydration because they make you urinate or sweat more than normal.
  • Illness
    People with diabetes, kidney disease, dementia and heart failure are particularly vulnerable and should pay deliberate attention to staying hydrated. It’s especially important to drink more fluids when you have a fever or diarrhoea.
  • Exercise
    The longer you exercise and the more intensive the exercise the more water you will need to replace that lost by sweating.
  • High altitude
    High altitude (more than 2,500 meters) affects hydration because you have to breathe faster to maintain adequate oxygen levels in your blood. The faster you breathe, the more water vapour you exhale.
  • Heat
    When it’s hot and humid, you sweat more. Without enough fluids, you can’t sweat enough to cool your body. The risks can vary from mild heat cramps or exhaustion, to potentially life-threatening heatstroke.

How can you prevent dehydration?

Drinking water regularly through the day is the best way to prevent dehydration. All drinks count towards your daily fluid intake, although you should try to avoid alcohol and caffeine as both are diuretics (you’ll be going to the toilet more and losing water from your body). Also beware of the high sugar content in sports drinks, which are best consumed post-exercise to re-hydrate and re-fuel. Some good options include milk, sugar free drinks, cordials and fruit teas.

Water doesn’t just have to come from the tap or from drinks. There are lots of other ways to help keep your body topped up. For example:

Soups – broths, soups, stews and other foods with a high liquid content also add to your water intake.

Salad and vegetables – vegetables like celery, tomatoes, lettuce and cauliflower are all great hydration helpers. The water content of a cucumber, for example, is 96.7%. And consuming lots of different colour vegetables in your diet is one of the best ways to ensure you’re getting all the vitamins and minerals you need for good health.

Whole fruits – fruits are also key to water intake. A watermelon is 92% water, raspberries and blueberries both contain around 85%, while blackberries are 88.2% water. Whole fruits also contain valuable nutrients and fibre, and their sugars are more easily absorbed into the body compared with fruit juices and smoothies.

Meat and fish – meat, poultry and fish can contribute to fluid intake. A flounder is 79% water, light chicken meat with skin is nearly 69% water and extra-lean minced beef contains 63% water.

Eggs – eggs also have a high water content at 75%, as well as being a rich source of protein and healthy fats.

Dairy – plain low-fat yoghurt is 89% water and low-fat ice cream is around 61%. Cheddar cheese can contain 40% water, and creamy varieties like cottage cheese can have even more!