Dehydration is caused by not drinking enough fluid or by losing more fluid than you take in. Fluid is lost through sweat, tears, vomiting, urine or diarrhoea.
The severity of dehydration can often depend on a number of factors, such as climate, level of physical activity and diet.
Dehydration is also linked to a number of other factors, which are outlined below.
Illness
Dehydration is often the result of an illness, such as gastroenteritis, where fluid is lost through persistent diarrhoea and vomiting.
Sweating
You can also become dehydrated after sweating excessively from a fever, heavy work in hot conditions or exercise and sport.
In these situations it's important that you drink regularly to replace lost fluids. It doesn't necessarily need to be hot for you to lose a significant amount of fluid from sweating.
Children and teenagers are particularly at risk because they may ignore the symptoms of dehydration or not know how to recognise and treat them.
Alcohol
Dehydration can also occur as a result of drinking too much alcohol. Alcohol is a diuretic, which means that it makes you urinate more.
The headache associated with a hangover indicates that your body is dehydrated. This is why it's important to drink plenty of water when you've been drinking alcohol.
Diabetes
If you have diabetes, you're at risk of dehydration because you have high levels of glucose in your bloodstream. Your kidneys will try to get rid of the glucose by creating more urine, so your body becomes dehydrated from urinating more frequently.
Read more about the different types of diabetes.
