1.What is oliguria, anuria and polyuria Under normal circumstances, the amount of urine excreted by each person in a day is about 1500-2000 ml. If the amount of urine in 24 hours is less than 400 ml, it is called oliguria, and less than 100 ml is called anuria. If the volume of urine in 24 hours exceeds 2500ml, it is called polyuria. 2.How to correctly analyze the causes of oliguria and polyuria Oliguria can be caused by various physiological or pathological factors, such as diarrhea, vomiting, peritonitis, etc., which can cause dehydration and thus insufficient effective circulating blood volume, as well as damage to the renal parenchyma, urinary tract obstruction, acute tubular necrosis, etc., which can also cause oliguria and should be noted when analyzing the causes of oliguria. Renal polyuria occurs for different reasons, but more commonly occurs in chronic renal insufficiency, which is due to renal tubular insufficiency, resulting in decreased urinary concentration. Once the symptoms of polyuria appear, it often means that the kidney function has been impaired and the urine specific gravity is mostly persistent low specific gravity urine. If it occurs during the polyuric phase of acute nephritis or acute renal failure, it often indicates that the condition is reduced or tends to improve. In patients with chronic interstitial kidney or tubular acidosis, polyuria is also often present due to tubular damage. The occurrence of renal polyuria is often mechanistically interconnected with polyuria due to other systemic diseases and is difficult to distinguish absolutely. For example, in primary aldosteronism, polyuria can be caused by high sodium stimulation of the hypothalamic volume center, or it can be caused by low potassium tubular damage resulting in reduced concentration function. 3. What is nocturnal polyuria In general, the daytime urine volume of a normal person should be greater than the nighttime urine volume. In young people, the ratio of daytime urine volume (6am-6pm) to nighttime urine volume (6pm-6am) should be 2:1. The ratio decreases with age and may drop to 1:1 by the age of 60. If the nighttime urine volume exceeds 1/2 of the daytime urine volume, it is called nocturia. 4, what are the common causes of increased nocturnal urination Under normal circumstances, after dinner generally do not drink much water, but also rarely eat, and in the body after sleep metabolism will also be reduced, so the blood flow is slow, the flow through the renal tubules of the original urine can be fully reabsorbed back into the circulatory system, so the total amount of nocturnal urine should be significantly less than the amount of urine during the day. In some cases, this can also lead to increased nocturia. Common causes include: in renal insufficiency, as the disease progresses, the number of surviving kidney units decreases, so metabolic wastes are retained in the body, causing the surviving kidney units to work continuously around the clock, which manifests as increased nocturia; in the presence of tubulointerstitial lesions, the concentration function of the kidney decreases, so the early stage of the lesion will also In the presence of interstitial renal tubular lesions, nocturia is also increased in the early stage of the disease because of the decrease in the concentrating function of the kidneys; other conditions such as voiding nocturia occur when there is water retention in the body, such as when the kidneys are bedridden at night when the blood circulation is improved, which increases the blood flow supply to the kidneys and facilitates the discharge of the retained water in the body, which is manifested as an increase in nocturia; in patients with mental stress (such as those with long-term enuresis) nocturia often occurs, which is called In patients with mental stress (such as long-term enuresis), nocturia often occurs, which is called preventive urination, and over time it will form a habit, that is, mental nocturia. 5.What is urinary incontinence The urine in the bladder cannot be controlled and flows out on its own, called urinary incontinence. It can be divided into two categories: true incontinence and pseudo-incontinence. True incontinence mainly includes two types. Active true incontinence refers to the loss of subjective control of urine as a result of a tonic contraction of the detrusor muscle, which causes urine to overcome the contraction of the sphincter muscle and drip out, and the bladder is often empty. Passive true incontinence is caused by damage to the sphincter, paralysis, or the presence of an abnormal fistula that causes the urine to drip out uncontrollably. If the bladder is often in a state of overfilling and the resulting urine is constantly dripping out, it is called pseudo-incontinence, also known as filling incontinence.