Fatigue: what are the signs of dehydration?

Dehydration is a condition in which the body loses more water than it takes in, leading to an imbalance in the fluids and electrolytes essential for its proper functioning. Water is crucial for many bodily functions, including regulating temperature, lubricating joints, and transporting nutrients and oxygen to cells.

What are the causes?

Dehydration can occur for a variety of reasons, such as :

• Excessive sweating: due to heat, intense exercise or fever.

• Insufficient water intake: not drinking enough water during the day.

• Illness: vomiting, diarrhoea or fever, all of which increase water loss.

• Medication: certain diuretics and other medications can increase urine production.

• Environmental conditions: hot, humid weather or high altitude.

What are the associated symptoms?

• Intense thirst: one of the first signs of dehydration, indicating that the body needs more water.

• Dry, sticky mouth: reduced saliva production leads to a feeling of dryness in the mouth.

• Dark urine: urine becomes more concentrated and darker in colour.

• Reduced urine production: a decrease in the frequency and quantity of urine.

• Dizziness or lightheadedness: a drop in blood pressure may cause dizziness.

• Dry skin: the skin may become dry and lose its elasticity.

• Headaches: dehydration can lead to headaches and migraines.

• Confusion or irritability: a lack of hydration can affect cognitive functioning, leading to changes in mood and difficulty concentrating.

• Rapid heartbeat: the heart may beat faster to compensate for the lack of fluid in the body.

• Lack of tears: in cases of severe dehydration, tears may no longer be produced, even when crying.

• Fatigue: a general feeling of weakness and tiredness may occur.

What is fatigue?

Fatigue is a complex state that goes beyond the simple sensation of drowsiness and the desire to sleep. It is the body’s response to a variety of internal and external factors, manifesting itself as a reduced ability to perform physical or mental activities that would normally be straightforward. Fatigue can be acute, resulting from intense effort, or chronic, developing over a long period of time.

The different types of fatigue (physical, mental and chronic)

There are different types of fatigue, each with its own different causes and consequences. Some people may suffer from all 3 types of fatigue at the same time. If this is the case for you, don’t hesitate to seek help from a health professional or make an appointment at a sleep clinic.

• Physical fatigue: physical fatigue often occurs after intense muscular effort, whether from sustained sporting activity or physically demanding work. It manifests itself as a feeling of heaviness in the limbs and can lead to a temporary reduction in physical strength. It can also result from a lack of sleep, when the body has not rested sufficiently and even simple tasks seem difficult to manage, leaving you feeling short of energy.

• Mental fatigue: mental fatigue results from prolonged mental strain, whether from complex intellectual tasks, sustained concentration or psychological stress. It can manifest itself as difficulty concentrating, reduced cognitive performance and a persistent feeling of mental exhaustion.

• Chronic fatigue: chronic fatigue is a more severe and persistent form of fatigue, often associated with underlying health conditions such as fibromyalgia, chronic fatigue syndrome or other medical conditions. It can have a negative impact on quality of life and requires appropriate medical attention.

Causes of fatigue

Lack of sleep and quality of sleep: Night-time is the time when the body regains its strength and the brain consolidates information gathered during the day. A lack of sleep, whether due to irregular bedtimes, sleep disorders or insufficient sleep, can lead to fatigue of varying degrees. Adults are generally advised to sleep between 7 and 9 hours a night to feel at their best. However, some people need as little as 5 hours’ sleep to be on top form, while others need 10 hours’ sleep to feel rested. Sleep is different for everyone, but it’s essential to get good quality sleep and maintain a regular bedtime routine to disrupting sleep patterns or even falling into hyposomnia.

Poor diet and nutritional deficiencies: Our bodies need energy and fuel to function properly. Food provides this fuel, so it is important to eat according to our needs. The more physically active you are, the more energy your body may require. If you spend a lot of time moving around and walking during the day, you need to eat enough to meet your energy needs; otherwise, you risk becoming tired. A diet lacking in nutrients can also contribute to fatigue. Deficiencies in iron, B vitamins and other nutrients can affect the body’s energy production. It is therefore essential to provide the body with the fibre, vitamins and fats it needs to help prevent episodes of fatigue.

Stress and overwork: Chronic stress and overwork are major contributors to fatigue. When the body is under constant stress, it releases stress hormones such as cortisol, which can disrupt sleep and deplete energy reserves.

To remedy this, you can learn stress management techniques such as meditation, deep breathing and yoga, which will help to reduce the effects of stress on the body. It is also essential to identify and reduce the sources of stress that punctuate our daily lives.

The main symptoms of fatigue

Recognising the signs of fatigue is essential if you are to address them in time. Symptoms can vary from person to person, but common signs include:

• Decreased energy: a general feeling of lack of energy and motivation, as well as feeling ‘drained’ throughout the day.

• Difficulty concentrating: problems focusing and paying attention to one or more simple tasks.

• Irritability: reduced tolerance of stress and frustration, easy to get upset and angry over small things.

• Sleep problems: difficulty falling asleep or maintaining good-quality sleep.

By understanding these signs, it becomes possible to adopt targeted approaches to prevent and alleviate fatigue, in particular by addressing underlying factors such as sleep, diet and, as we shall see, hydration.

A powdered electrolyte drink enriched with coconut water, taurine and four minerals (magnesium, potassium, calcium and zinc) for optimal hydration. It helps reduce fatigue thanks to magnesium, and supports muscle function thanks to potassium and calcium. Easy to mix in your water bottle, before, during or after exercise, upon waking or whenever you feel tired. With no added flavourings or sweeteners, it also fits into a beauty routine or can be enjoyed the morning after a night out.

If there’s one key element to the body functioning properly, it’s water. In fact, water is the main component of the human body, accounting for around 65 per cent of its composition – more than half. So, to stay healthy, don’t forget to stay hydrated! 

The role of water in the body

Water is essential for life and plays a crucial role in the body’s proper functioning. Around 65 per cent of the human body is made up of water, making it an indispensable component for many biological functions. It helps regulate body temperature, aids digestion, facilitates the absorption of nutrients and helps eliminate waste.

When the body is well hydrated, cells function optimally and can easily maintain an adequate energy level. Water also facilitates the transport of nutrients to the cells, thereby promoting better utilisation of nutrients for energy production.

Effects of dehydration on energy and performance

Dehydration and reduced energy: Dehydration can quickly lead to a drop in energy levels. When the body lacks water, blood circulation can become less efficient, reducing the supply of oxygen and nutrients to the cells and leading to a feeling of tiredness.

Reduced physical and mental performance: Inadequate fluid intake can temporarily impair physical performance and concentration. Studies have shown that even mild dehydration (1%) can lead to reduced physical endurance, impaired concentration and diminished cognitive function.

Symptoms of dehydration and their impact on fatigue

Recognising the signs of dehydration: It is essential to recognise the symptoms of dehydration, as if left unrecognised they can lead to significant persistent fatigue. Common signs include feeling thirsty, a dry mouth, headaches, dry skin and dark urine. If you feel dizzy or nauseous, this may be a sign of severe dehydration so it is important to drink something straight away! On average, it is recommended that adults weighing around 50 kilos drink at least 1.5 litres of water a day. 

The vicious circle of dehydration and fatigue: Dehydration can create a vicious circle with fatigue: a lack of water leads to fatigue, whilst fatigue reduces the sensation of thirst. To stay healthy and avoid feeling tired, it is essential to drink water regularly, even before you feel thirsty.

Our advice

To make regular hydration a habit, carry a bottle of water with you. That way, you can drink regularly and avoid becoming dehydrated.

The importance of hydration in preventing fatigue

Maintaining adequate hydration is an essential pillar of fatigue prevention. Water is the main constituent of our body and is involved in almost every biological process. To prevent fatigue, it is crucial to constantly meet the body's water needs. Taking a proactive approach to hydration can help maintain optimal energy levels.

Hydrating foods and recommended drinks

• Infusions and herbal teas: Caffeine-free infusions and herbal teas are excellent alternatives for diversifying your water intake. Options such as camomile, mint and green tea are ideal for combining goodness and pleasure, and some will even help you sleep!

• Naturally flavoured water: For those who find ordinary water a little boring, water flavoured naturally with fruit and herbs is a delicious and hydrating option. It offers a healthy alternative to sugary and artificially flavoured drinks.

• Drink before, during and after exercise: During physical activity, the body loses water through pores and perspiration. It is therefore essential to compensate for this loss by drinking water before, during and after exercise to maintain optimum hydration.

Our tips for maintaining good daily hydration

1. Carry a bottle of water with you: keeping a bottle of water to hand throughout the day helps you to hydrate regularly. This makes it easier to meet your water requirements, whether at work, at home or on the move.

2. Listen to thirst signals: thirst is a natural indicator of our body's need for water. Listening to these signals and responding to thirst is a simple and effective way of maintaining optimal hydration.

3. Structure your water intake: spreading your water intake throughout the day is a more effective approach than drinking large quantities all at once. This allows more regular absorption and supports the body’s biological functions. Given that it is recommended to drink at least 1.5 litres of water a day, we advise you to drink 1 litre in the morning and 1 litre in the afternoon. Avoid drinking too much in the evening so that you don’t have to get up to go to the toilet at night, as this will only disrupt your sleep cycle.

4. Eat hydrating foods: as well as drinking water, you can easily incorporate water-rich foods, such as fruit and vegetables, to meet your daily needs. Watermelons, cucumbers and oranges are excellent options for keeping hydrated and enjoying yourself at the same time!

If you follow these tips, you'll have no trouble preventing the fatigue associated with lack of hydration. But don’t forget to be gentle with yourself and your body - some moments in life can be stressful, so it’s never too late to take care of yourself and learn to listen to your body!

By incorporating conscious hydration into your daily routine, you can help support your general well-being and optimise your energy levels.

Laura is a health, beauty and lifestyle writer. Passionate about travel and gastronomy, she shares nutritional advice on combining pleasure and wellness. Through her articles, she aims to provide meaningful information and practical advice to nourish both body and mind.