Dehydration refers to the lack of the necessary amount of water in the body. Water is the principal constituent of all living beings, and lack of water can disrupt almost all body functions. Dehydration can occur if there is less water intake or greater fluid loss from the body. It is a common condition and occurs mildly in almost all humans due to certain physiological or environmental factors. However, there are some diseases and conditions in which extreme water loss leads to severe dehydration. Such cases require immediate medical attention as they may prove to be lethal if not treated properly within the given period.
There are various causes of dehydration, including physiological, environmental, pathological, and other factors. It is a normal process to lose water by urination, defecation, breathing, sweating, or tears. If you perform any strenuous activity such as exercise or lifting weights, you may lose a greater than normal amount of water by sweating. Also, it has been noticed that people with stress or anxiety often tend to forget to drink water. Frequent urination can also lead to dehydration, such as in patients with diabetes, kidney diseases, or psychological disorders. Some medications, such as diuretics, increase fluid loss from the body, resulting in dehydration. Electrolyte disturbance such as hyponatremia can cause the body to lose more water. A hot or humid environment is one of the major causes. It causes excessive water loss through the skin and respiratory system. Any major trauma injury that causes blood loss or burns can also reduce the amount of water necessary for survival. Severe diarrhea or vomiting due to gastrointestinal diseases are other causes.
Signs and symptoms of dehydration depend upon the severity of dehydration. Mild dehydration is common and can result in an increase in thirst, lesser urination, darker color of urine, dry skin, and dry mouth. The frequency of urination decreases, and its color darkens with increasing dehydration. Moderate dehydration may result in less urination, dizziness (primarily upon standing up), and fainting episodes. Severe dehydration or loss of over 15% of body water presents with extreme neurological symptoms such as fainting, irritability, severe headache, numbness of limbs, seizures, disorientation, etc. The body temperature may rise to cope with decreased sweating. If it is not addressed and treated on time, it may lead to the death of the affected person.
The diagnosis of dehydration is usually made based on presenting symptoms and clinical examination. Your doctor may check your vitals, such as pulse, blood pressure, temperature, breathing rate, etc., to determine if the blood volume is less than sufficient. A weak pulse and low blood pressure may be a sign of moderate to severe dehydration. A general clinical examination may be performed to notice dry mouth, dry skin, and other neurological symptoms. If necessary, your doctor may ask for an electrolyte test and urinalysis. A blood sample is drawn for an electrolyte test to measure the amount of necessary electrolytes, e.g., sodium, potassium, etc., in blood. Urinalysis can help in determining the severity of dehydration.
Other diseases that may present with similar symptoms as dehydration include diabetic ketoacidosis, pathologic hypernatremia, anemia, hypo or hyperthyroidism, hypoglycemia, anaphylactic shock, cardiovascular shock, sepsis, etc.
The primary treatment method to treat mild dehydration is to drink a greater amount of water. Freshwater is preferred over juices, sports drinks, alcohol, or any other type of fluid. Oral rehydration salts may be given as well to fulfill any electrolyte imbalance. In moderate or severe dehydration cases, intravenous fluid solutions are given until the vital signs become stable. It is suggested to avoid strenuous work or working in hot/humid environments to prevent further dehydration. Urine output should be checked regularly in patients with severe dehydration. Intake of diuretic medication should be avoided at all costs during treatment of severe dehydration. Dehydration is treated symptomatically and requires no particular medication.
Mild to moderate dehydration can be managed well with an increased intake of fluids and necessary electrolytes. The prognosis of severe dehydration depends on water loss and other factors. If emergency treatment is given in the form of intravenous fluids and electrolytes, the vital signs may become stable again. Loss of over 15 to 25% of body water can cause extreme neurological dysfunction and may lead to death.
Dehydration can be prevented by drinking an adequate amount of water every day. The suggested amount is eight glasses per day, but it can vary depending on the age and bodyweight of the individual. If you have stress or anxiety, it is better to keep reminders that alert you to drink water after a certain interval of time. To avoid dehydration, caffeine, alcohol, and carbonated drinks should be lessened and replaced with fresh water.
Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 16, 2023.
Dehydration - Illnesses & conditions | NHS inform
Dehydration - Symptoms and causes - Mayo Clinic