Liver Terms and Definitions


A protein made in the liver that assists in maintaining blood volume in the arteries and veins. If the liver is damaged, then the albumin can drop to very low levels, which may cause fluid to leak into the tissues from the blood vessels, resulting in edema or swelling. In acute liver failure, there is an accumulation of fluid in the abdomen that is known as “ascites”.


A large, abnormal accumulation of fluid in the abdomen that can occur due to liver failure, cirrhosis and liver cancer. This condition requires immediate medical attention.

Cholic Acid and Cholate

Cholic acid, along with chenodeoxycholic acid, is one of the two major bile acids produced by the liver, where it is synthesized from cholesterol. These two major bile acids are roughly equal in concentration in humans. Salts of cholic acid are called what is known as cholates. Cholates are the major primary bile acid produced in the liver that facilitates fat absorption and cholesterol excretion. An ester or salt of the bile acid cholic acid that is synthesized in the liver from cholesterol, with surfactant and signaling activities in the liver and intestine. In the intestine, cholate acts as a surfactant that promotes the absorption of dietary lipids and fat-soluble vitamins. In the liver, cholate’s surfactant activity facilitates biliary excretion of xenobiotics and metal cations. Cholate may also be used as a biomarker for hepatotoxicity.

Clinical Outcome (Endpoint)

Clinical outcomes (endpoints) are outcome measures referring to occurrence of disease, symptom, sign or laboratory abnormality constituting a target outcome in clinical research trials. The primary endpoint of a clinical trial is the endpoint for which the trial is powered. Secondary endpoints are additional endpoints, preferably also pre-specified, for which the trial may not be powered. Surrogate endpoints are trial endpoints that have outcomes that substitute for a clinical endpoint, often because studying the clinical endpoint is difficult.

Liver Cirrhosis

Cirrhosis is a progressive liver condition characterized by loss of functional hepatocytes with concomitant connective tissue and nodule formation in the liver. Alcohol and chronic viral hepatitis (such as chronic hepatitis B and C) can cause continuous inflammation of the liver, which can lead to excess scar formation or fibrosis. Scarring results in the loss of liver cells and impairs liver function.  The morphological and physiological changes associated with the disease substantially affect drug pharmacokinetics.


Term for describing the development of measurable deterioration or clinical complication in patients with chronic liver disease.


Serious brain function abnormalities experienced by some patients with advanced liver disease. Symptoms most commonly include confusion, disorientation, insomnia, and may progress to a coma.


A medical procedure where a doctor puts a tube-like instrument into the body to look inside. Unlike most other medical imaging devices, endoscopes are inserted directly into the organ. There are many types of endoscopy, each of which is designed for looking at a certain part of the body.


Naturally occurring chemical substances in the human body that help a chemical reaction take place.


Growth of fibrous tissue in the liver where there is usually liver cell damage or destruction. Fibrosis can lead to cirrhosis, an even more serious liver disease.


The field of medicine that focuses on the function and disorders of the GI system, which includes the esophagus, stomach, pancreas, intestines, and liver.


Hemochromatosis is a disorder that interferes with the body’s ability to break down iron, and results in too much iron being absorbed from the gastrointestinal tract.

Hepatic Impairment

Liver failure is the inability of the liver to perform its normal synthetic and metabolic function as part of normal physiology.

Hepatic Venous Pressure Gradient (HVPG)

Currently, the most commonly used parameter to directly measure portal pressure is the Hepatic Venous Pressure Gradient (HVPG). HVPG represents the gradient between pressures in the portal vein and the intra-abdominal portion of inferior vena cava.

Hepatitis B

Formerly called “serum hepatitis”, it is caused by the hepatitis B virus (HBV). It is spread primarily through blood, unprotected sex, shared needles, and from an infected mother to her newborn during the delivery process. There is a safe vaccine for HBV.

Hepatitis C

Formerly known as “non-A, non-B hepatitis”, it is caused by the hepatitis C virus (HCV). It is spread through infected blood, primarily in those who use illicit street drugs and those who received blood transfusions prior to 1992 (the first year that a blood test for HCV became available for screening the blood supply). There is no vaccine.


Hepatology is the medical specialty focusing on treatment of diseases, disorders, and conditions of the liver. Hepatology is a subspecialty of internal medicine, and is often practiced in conjunction with gastroenterology, another subspecialty of internal medicine. Hepatologists treat liver diseases such as all types of hepatitis, and cirrhosis of the liver.


Hepatotoxicity implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications. The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents.

Liquid Chromatography-Mass Spectrometry (LC-MS)

An analytical chemistry technique that combines the physical separation capabilities of liquid chromatography (or HPLC) with the mass analysis capabilities of mass spectrometry. LC-MS is a powerful technique with has very high sensitivity and specificity. Generally its application is oriented towards the specific detection and potential identification of chemicals in the presence of other chemicals (in a complex mixture).

Liver Biopsy

The removal of a small piece of tissue from the liver using a special needle. The tissue is examined under a microscope to look for the presence of inflammation or liver damage.


Pharmacodynamics, often described as what a drug does to the body, is the study of the biochemical, physiologic, and molecular effects of drugs on the body and involves receptor binding (including receptor sensitivity), postreceptor effects, and chemical interactions. Pharmacodynamics, with pharmacokinetics (what the body does to a drug, or the fate of a drug within the body), helps explain the relationship between the dose and response (the drug’s effects).  All drugs produce their effects by interacting with biological structures or targets at the molecular level to induce a change in how the target molecule functions in regard to subsequent intermolecular interactions.

Pharmacokinetics (PK), often described as what the body does to a drug, is a discipline within pharmacology dedicated to understanding the impact of substances administered to a living organism. The substances of interest include any xenobiotic chemical substances such as pharmaceutical drugs. It attempts to analyze chemical metabolism and to discover the fate of a chemical from the moment that it is administered up to the point at which it is completely eliminated from the body.

Portal Circulation

Portal Circulation refers to the circulation of the blood from the small intestine to the liver, via the portal vein.

Portal Vein

The hepatic portal vein is a vein in the abdominal cavity that drains blood from the gastrointestinal tract and spleen to the liver.


Enlarged veins within the gastrointestinal tract that form as a result of cirrhosis.