Many diseases and disorders, as a side effect of their functions, produce excess fluid which, because it is not part of the body's natural process, often has nowhere to go. This liquid, called ascitic fluid, is often forced to accumulate in the part of the body where there is the most extraneous space: the abdomen. This condition in which ascitic fluid accumulates within the abdomen is called ascites. The specific ascites definition is that it is a condition where excess fluid builds up in the peritoneal cavity, which is the space in the body that separates the abdominal wall from the internal viscera, or organs, contained with the abdomen. Ascitic fluid can be composed of a number of different materials, according to the ascites definition, which is incumbent on the nature of the disease that caused the ascites. While the common designation is now ascites, an ascites definition in older medical textbooks may label this condition as peritoneal fluid excess, hydroperitoneum, or abdominal dropsy. 

Ascites can be caused by a number of conditions, but it is most often the result of cirrhosis of the liver, where the liver ceases to function and fluids that would normally be processed by the liver are instead dispersed into the abdominal cavity. When studying ascites, definitions in some categories intimately affiliate it with cirrhosis, but ascitic fluid build up can be associated with other conditions as well, such as portal hypertension, which forces blood into other alternate channels due to blockages in the circulatory system.  Ruptures, due to ulcerations in the digestive system can also cause ascites, as can some forms of cancer. 

Symptoms of ascites can be varied, as there are mild cases that many may simply associate with wait gain or mild obesity. Ascites definitions generally classify the condition in three grades. Grade 1 is very mild ascites, with limited fluid buildup. Grade 2 ascites has enough fluid buildup that some distention is noticceable.  Grade 3 has extremely visible distention and atrophy of the abdomen, which is accompanied by fluid reactions in the abdomen. Even mild ascites can cause some health problems, such as shortness or breath or diminished physical activity. Severe ascites usually results in extreme shortness of breath, exhaustion, coughing, and cardiovascular overexertion due to the extra weight. The ascitic fluid, in severe cases, places extreme pressure on the diaphragm beneath the lungs, and can be a major impediment to normal breathing, causing a systemic strain on the entire body. Leg swelling, propensity for bruising, gynecomastia, and hematemesis (the vomiting of blood) can also be symptoms of ascites. Definition of mental capacity can even be influenced by ascitic fluid excess when it moves it is dispersed throughout the body. Fluid retention can also cause fluid retention in the kidneys, which can increase blood pressure. 

In diagnosing ascites, definition of the the abdomen is a primary focus. Generally, ascites suffers will exhibit was is called bulging blanks, where the abdomen will be noticeable distended on the sides instead of just in the front, due to shifts in ascitic fluid. Shifting dullness, where the distension actually shifts due to movement of the body in a lying state and the redistribution of ascitic fluid, is also a hallmark of ascites.  A common examination in extreme ascites will be the ease of fluid movement in the abdomen. This is commonly called a fluid thrill or a fluid wave, where a ripple effect is noticeable across a distention when placing pressure on one side.) 

When ascites is strongly suspected, further examination can be made via ultrasound observation of the peritoneal cavity. It is also common to perform a blood count, examine liver enzymes, test blood coagulation, and establish a metabolic profile. If a blood count or enzyme count is low, and blood will not coagulate properly, it could be indicative of excess fluid in the system, which then supports ascites. Definition of the content of the ascitic fluid is also vital, and often removed through paracentesis (draining of a body cavity with a needle). The draining of fluid itself may provide temporary relief, but often treatment of whatever caused the ascites will be key to curing the condition. To this end, ascitic fluid is analyzed for its content and composition. 

Ascites treatment is usually based on the severity of the condition, but there are multitude of common factors.  Generally, fluid loss is the goal, but at a controlled rate, commonly about about one pound of fluid weight per day (this may sound considerable, but it is not uncommon for some sufferers of severe ascites to carry an additional twenty to thirty pounds of extra weight in ascitic fluid). To this end, use of diuretics, as well as restriction of salt intake and water intake, in undertaken to increase urination and kidney function to dispel the ascitic fluid naturally.  In extreme cases multiple paracentesis treatments may be necessary to remove fluid at a rate to which the body can gradually become readjusted to.