What is the cause of ascites?

Ascites is not a single disease, but a symptom of severe liver disease, the most common of which is cirrhosis. When a patient has cirrhosis, it often leads to portal hypertension. Because the hydrostatic pressure of the visceral vascular bed gradually increases, the body's tissue fluid is absorbed less at this time, and it will flow into the abdominal cavity, thus forming ascites. After the formation of ascites, the harm to the patient is relatively large. At this time, fluid extraction treatment should be carried out in time, and the patient should eat more high-protein foods. In addition to liver disease, if there is a lymphatic reflux disorder, it is easy to develop such symptoms of ascites, which is particularly harmful to patients.

1. Portal hypertension:

Due to the destruction of the physiological structure of the liver parenchyma, the hydrostatic pressure of the visceral vascular bed in the abdominal cavity increases, and the reabsorption of tissue fluid decreases and leaks into the abdominal cavity, forming ascites.

2. Hypoalbuminemia:

The occurrence of ascites is a long development process of liver disease. Prior to this, liver lesions affect the synthesis and uptake of protein, eventually leading to malnutrition and deficiency or synthesis disorders of various nutrients. When the albumin content is lower than 31g/l, the plasma colloid osmotic pressure decreases, causing extravasation of blood components.

3. Other factors:

These include destruction of liver structure, excessive lymph production that cannot be drained through the thoracic duct, secondary aldosterone increase leading to increased renal sodium reabsorption, and increased secretion of antidiuretic hormone leading to increased water reabsorption. As well as insufficient effective circulating blood volume leading to increased sympathetic nerve activity, decreased prostaglandin, atrial, and kallikrein-kinin activity, leading to decreased renal blood flow, sodium excretion, and urine output.

4. Lymphatic reflux disorder:

The human body's lymphatic circulation, also known as the third circulation, refers to a circulatory system located outside the arteries, veins, and capillaries. Normal people have lymphatic circulation everywhere, especially between the liver sinusoids and hepatocytes, where there is abundant lymph fluid. Due to the lesions, the liver not only increases the portal vein pressure, but also increases the lymphatic pressure, causing the lumen to expand, lymphatic reflux obstruction, and lymph overflow, which becomes the cause of hepatic ascites.

5. Increased aldosterone, etc.

It is also a common cause of hepatic ascites. Under normal circumstances, aldosterone (and possibly antidiuretic hormone) are inactivated in the liver. When liver function is impaired, it can cause insufficient inactivation of aldosterone and antidiuretic hormone, resulting in secondary increase in aldosterone and antidiuretic hormone. Both hormones can cause increased reabsorption of water and sodium in the distal renal tubules, thereby causing further retention of water and sodium and forming hepatic ascites.