Too much of a good thing – thirst and the right amount to drink
Many people will be familiar with the urgent feeling of thirst after a well-seasoned meal or a hike in warm weather – you can’t get the bottle of water open fast enough, perhaps even emptying it in one go, the body gets what it needs. But what if thirst becomes a constant companion and you can hardly keep up with drinking? In addition to some illness-related causes of increased drinking – polydipsia – such a persistent feeling of thirst can also be present if no physical cause can be found. This is then referred to as primary polydipsia. Drinking lots of healthy fluids has long since become a trend. However, as with everything, too much of a good thing is also harmful – you should not lose sight of the amount you need to drink to meet your physical needs. But sometimes this is difficult. Where does the seemingly causeless thirst come from?
Getting to the bottom of thirst
Polydipsia is often due to physical causes, such as type I and II diabetes, Cushing’s syndrome, hepatopathies, kidney and thyroid diseases, diarrhea, vomiting or fever. This leads to an increased loss of fluid through the skin, urine or bowel movements, which must be compensated for. This is especially important for older people, as they are particularly easily affected by dehydration symptoms. Reduced cognitive performance, confusion and dizziness may occur. Here, the increased feeling of thirst leads to increased fluid intake. This can compensate for the fluid deficit. This is an important measure in addition to adequate treatment of the underlying condition.
When the psyche makes you thirsty
If there is no underlying physical cause for an increased feeling of thirst, this is called primary polydipsia. The reasons for this are often to be found in the psyche of those affected – for example in the presence of illnesses such as schizophrenia, during a manic phase of bipolar psychosis or in the case of anorexia nervosa. The feeling of thirst is also partly due to the anticholinergic effect of medications such as antidepressants, beta blockers, incontinence and sedatives, which are often used in the treatment of elderly people and cause dry mucous membranes in the mouth, which in turn leads to increased drinking. The dieting efforts of predominantly younger women often lead them to reach for a glass of water too often in order to supposedly counteract feelings of hunger.
But can you really drink too much?
Can’t drink enough water?
Water has long been regarded as an elixir of life that is essential for physical and mental health. As an essential component of the human body, it needs approx. 1.5 to 2 liters of fluid per day in order to function optimally. This amount should be adjusted according to temperature and physical activity https://www.gesundheit.gv.at/leben/ernaehrung/info/fluessigkeitsbedarf. The most suitable drink is water or mineral water, which provides the body with sufficient calorie-free fluids and additional minerals and is also an optimal means of transport for nutrients and waste products from bodily excretion processes. Even a fluid loss of 1-2% of the body mass causes the body to react sensitively. The blood thickens, the transport of nutrients and oxygen via the blood decreases, the concentration decreases, thromboses and seizures can occur. If you drink a sufficient amount regularly throughout the day, your fluid balance remains balanced, you feel good and physical processes run smoothly.
But what happens if you drink more than you need? The human body can absorb approx. 500 to 800 ml per hour, any more than this is excreted. Excessive drinking can be compensated for in the short term. However, if you drink too much in the long term, this is just as harmful to the body as drinking too little. This is partly due to a loss of electrolytes, for example, which is caused by increased fluid excretion via the kidneys. In particular, hyponatremia, the most common electrolyte disorder caused by the increased urine volume, can quickly become life-threatening in the presence of an underlying disease such as heart failure and is initially accompanied by dizziness and an increased tendency to fall. The causes of the increased feeling of thirst should be clarified and drinking behavior adjusted.
What to do about thirst?
In the case of polydipsia due to physical causes, adequate treatment of the underlying disease should first and foremost be carried out by a doctor. In the case of mental illness, therapeutic support, such as behavior modification, can also help. It is also important to substitute electrolytes if deficiencies have already occurred. Athletes like to use isotonic drinks here. They are used to compensate for the electrolytes excreted through sweating and increased excretion after a training-related increase in drinking. For self-treatable conditions such as diarrhea, lost minerals can easily be replenished with vegetable broth, which also relieves thirst. If there is an increased amount of drinking due to illness with increased urinary excretion and the resulting loss of electrolytes, substitution should always be carried out under medical supervision.
Dry oral mucous membranes lead to an increased feeling of thirst. To prevent too much fluid intake, fruit juices or unsweetened fruit teas, for example, can be chosen as drinks. Their acidity stimulates saliva production, the oral mucosa is better moisturized and the feeling of thirst is reduced. A similar effect can be achieved by chewing gum or sugar-free fruit sweets.
Back to balance – even when drinking
As healthy and important as it is to drink enough, it is also important to maintain a balance and provide the body with exactly as much fluid as it needs. If you drink too much for a short time, for example after increased physical exertion or eating spicy food, your body can compensate for this without hesitation. A permanent excess of fluids, on the other hand, is just as harmful as a lack of fluids. Here it is important to get to the bottom of the causes of the greatly increased need to drink, which makes you constantly reach for a glass. In addition, a solution must be found that leads to a balanced relationship between need and demand.
