Do kidneys filter blood?

The kidneys are a very important part of the human body and are known as the foundation of the five elements of the human body. The main function now is to detoxify the body and maintain the fluid balance in the body, as well as to maintain the balance of electrolytes and acid-base, which is a very important part of the body. But not everyone is clear about the function of kidneys. Then some people may have questions at this time: Do kidneys filter blood? Does it help with blood filtration?

1. Detoxification

The kidneys have millions of glomeruli, which are like small filters and together make up the kidney, a large detoxification "filter purifier". The human body's metabolism produces a lot of metabolic waste and toxins every day, which need to be constantly eliminated.

When blood carrying metabolic waste and toxins flows into the kidneys through the renal arteries, they are discharged from the body through these tiny "filters", making the blood clean and purified.

2. Maintain fluid balance in the body

During the filtering process, the kidneys not only remove metabolic waste and toxins from the blood, but also excrete excess water absorbed by the body through food and water intake, as well as produced by the metabolic process. This water is discharged from the body through the renal pelvis, renal calyces, ureters, and bladder to maintain fluid balance in the body.

If your kidneys are functioning normally, but you sweat too much, or lose a lot of fluid due to vomiting or diarrhea, or drink too little water, your kidneys will produce less urine, ensuring the necessary amount of fluid in your body. On the contrary, if you drink too much water, beyond the body's needs, your urine output will increase, which will not lead to weight gain or even edema.

Normal daily urine volume is 2000-2500ml.

Nighttime (8:00 pm to 8:00 am) urine volume should not exceed 750 ml.

When kidney lesions occur, there will be increased nocturia, decreased urine volume, and even oliguria or anuria.

3. Maintain electrolyte and acid-base balance

Whether the blood potassium increases or decreases, the blood sodium increases or decreases, the blood calcium increases or decreases, or the blood phosphorus increases or decreases, it all depends on the kidneys to take care of it and maintain it at a normal level that is neither too high nor too low. This is called "maintaining electrolyte balance." If there is too much acid or alkalinity in the body, the kidneys must be used to regulate it and maintain it at normal levels. This is called "maintaining acid-base balance."

The burden on the kidneys is too heavy! Once renal function is damaged, serious complications such as hyperkalemia, hyperphosphatemia, hypocalcemia, metabolic acidosis, etc. will occur, endangering life!

4. Participate in blood pressure control

Blood pressure is the pressure of blood against the walls of your blood vessels. Healthy kidneys help control blood pressure at normal levels. Once the kidneys are diseased, blood pressure will be affected in many ways. If the urine volume decreases, water and sodium are retained in the body, which will cause a volume-load increase in blood pressure; when there is kidney disease, the secretion of renin-angiotensin and vasopressin increases, causing renal hypertension.

Increased blood pressure will further accelerate kidney damage and cause damage to important organs in the body such as the heart and brain. In short, no matter what stage kidney disease has reached, the progression and treatment of the disease are closely related to controlling blood pressure.

5. Maintain bone health

As Chinese medicine theory says, "the kidneys govern the bones." Although the term "kidney" in traditional Chinese medicine has a broader meaning, the kidneys do play an important role in maintaining bone health. Vitamin D3 needs to be activated by kidney hydroxylation into active vitamin D3 (calcitriol) in order to play its role in regulating calcium absorption, maintaining bone health, regulating immune function, and protecting arteries.

Phosphate in the body is excreted through the kidneys. Once renal function is damaged, phosphorus cannot be excreted, and hyperphosphatemia will inhibit active vitamin D3, leading to secondary hyperparathyroidism, causing the bones to release calcium, resulting in renal osteodystrophy, and inducing arterial calcification, heart valve calcification, and soft tissue calcification.

6. Produce red blood cells

The kidneys secrete a hormone called erythropoietin, which helps the body produce sufficient red blood cells when there are sufficient hematopoietic raw materials (such as folic acid and iron supplements). Once the kidneys are diseased, the secretion of erythropoietin decreases, leading to renal anemia.

Disclaimer: This article is an original article. Please contact Kidney Butler for authorized reprinting. Kidney Butler provides popular science information. Because each patient has different medical conditions, the specific treatment should be based on the doctor's advice.