The basis for judging different types of dehydration is:

Dehydration refers to a symptom of metabolic disorders caused by the human body consuming a large amount of water due to lesions, and can not be replenished in time.

When the human body is in a high temperature environment, or sweating profusely after exercise, it can cause dehydration, or due to high heat, a variety of high metabolic states (such as hyperthyroidism, etc.), or due to anorexia, oral cavity, esophageal and other diseases can not eat and drink, <>

Dehydration can be caused by vomiting, abdominal diarrhoea, gastrointestinal decompression, gastrointestinal fistula, diuresis, renal disease, polyuria, or polyuria due to insufficient secretion of antidiuretic hormone by the posterior pituitary gland. Shortness of breath can also cause respiratory dehydration.

In people with normal thirst, hyperosmolar dehydration is rarely caused when water is available and able to drink, because a slight increase in plasma osmolality in the early stages of water loss stimulates the thirst center.

Plasma osmolality is restored after drinking water. Dehydration can be divided into three types according to the osmotic pressure of the extracellular fluid. If dehydration is predominant, it is called hyperosmolar (primary) dehydration; Sodium loss is predominant, called hypotonic (secondary) dehydration; Water and sodium are each lost in proportion to their plasma content, which is called isotonic dehydration.

In hyperosmotic dehydration, a 5% glucose solution should be given because of the high sodium concentration in the blood. Severe hypernatremia can be given intravenously or 3% dextrose solution.

The main basis for judging the nature of dehydration is the change in osmolality of body fluids.

1. In the dehydrated state, due to the decrease of water in the human body, the concentration of solutes (such as electrolytes, glucose, etc.) in the body fluid increases, which correspondingly increases the osmotic pressure of the body fluid. Therefore, by measuring the osmotic pressure changes of body fluids, it is possible to determine whether a person is in a state of dehydration and the severity of their degree of dehydration.

2. Other indicators, such as urine output and electrolyte concentration in the blood, can also be used as one of the reference indicators for judging dehydration. It should be noted that the symptoms and indicators of different degrees of dehydration are also different, so it is necessary to make a comprehensive judgment according to the specific situation. At the same time, when judging whether dehydration is dehydrated, it is necessary to combine clinical manifestations and laboratory test results and comprehensive analysis to reach a final diagnosis.

Causes of dehydration:

1. Heavy sweating: In the case of high temperature environment, strenuous exercise or fever, the human body will sweat profusely, resulting in fluid imbalance.

2. Insufficient drinking water: If the intake of enough water is not enough to make up for the loss of water in the body, dehydration will occur.

3. Vomiting or diarrhea: These conditions can lead to the loss of water and electrolytes, which in turn can lead to dehydration.

4. Decrease in urine output: When urine output decreases, the body cannot effectively remove metabolites, resulting in an increase in solute concentration in the body, thereby causing dehydration.

The severity of dehydration can be classified according to the degree of fluid loss, and it is generally divided into three levels: mild dehydration, moderate dehydration, and severe dehydration. Mild dehydration can be relieved by drinking plenty of fluids, while moderate and severe dehydration require prompt medical attention**. Ways to prevent dehydration include drinking plenty of water, avoiding exposure to the sun in a hot environment, and paying attention to drinking and eating nutrients.

Answer]: A mild dehydration: water loss of 5% of body weight (30 50ml kg).

The spirit is slightly worse to make dates, and he is slightly irritable. **Slightly dry, elastic acceptable. The eye socket and fontanelle are slightly sunken, there are tears when crying, the mucous membrane of the lips is slightly dry, and the urine output is slightly reduced.

Moderate dehydration: water loss of 5% 10% of body weight (50 100 ml kg). Sluggish or irritable, pale, dry, poor elasticity, obvious sunken eye sockets and fontanelles, less tears when crying, dry mucous membranes of the lips, slightly cooler limbs, and significantly reduced urine output.

Severe dehydration: water loss of more than 10% of body weight (100 120 ml kg). He was seriously ill, extremely depressed, his expression was indifferent, and he was even drowsy and Hu Yuanzhi was in a coma.

**Gray or patterned, dry, very poor elasticity. The eye sockets and antecedents are deeply sunken, there are no tears when crying, and the mucous membranes of the lips are extremely dry. At the same time, there are symptoms of shock due to significant decrease in blood volume, such as low heart sounds, rapid pulse, decreased blood pressure, cold limbs, and little or no urine.

Option A is wrong, moderate dehydration water loss 50 100ml kg.