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Medical Terminology


Acute Hepatic Porphyria (AHP) refers to a family of rare genetic diseases characterized by potentially life-threatening attacks and, for some people, chronic (ongoing and sometimes lifelong) pain and other symptoms that interfere in their ability to live normal lives.

There are four types of AHP. Acute Intermittent Porphyria (AIP) makes up 80% of all cases. The remaining types are:

  • Acute Intermittent Porphyria (AIP – makes up 80% of all cases)
  • Variegate Porphyria (VP)
  • Hereditary Coproporphyia (HCP)
  • ALAD Deficiency Porphyria (ADP)

AHP is a hereditary disease, meaning that it can be passed from parents to children.  This can occur if either one or both parents carry the defective gene, depending on the AHP type. Men and women inherit the disease equally as often; however, women tend to suffer symptoms more often than men.

Acute intermittent porphyria (AIP) is a rare metabolic disorder that is characterized by partial deficiency of the enzyme hydroxymethylbilane synthase (also known as porphobilinogen deaminase). This enzyme deficiency can result in the accumulation of porphyrin precursors in the body.

Aminolevulinic acid, an endogenous non-proteinogenic amino acid, is the first compound in the porphyrin synthesis pathway, the pathway that leads to heme in mammals, as well as chlorophyll in plants. ALA is used in photodynamic detection and surgery of cancer.

ALAD Porphyria (ADP) is a very rare genetic metabolic disease characterized by almost complete deficiency of the enzyme delta-aminolevulinic acid (ALA) dehydratase. In ADP, the gene responsible is ALAD which produces the enzyme δ-aminolevulinic acid dehydratase. Deficiency of this enzyme leads to the accumulation of the toxic porphyrin precursor ALA, which can potentially result in a variety of symptoms. Symptoms vary from one person to another, but usually come from the neurological and gastrointestinal systems. This disease is inherited as an autosomal recessive disorder. ADP is more severe than the other acute Porphyrias and can present in childhood. Only ~10 cases have been reported worldwide and all reported cases have been males, in contrast to the other acute Porphyrias where more women are symptomatic.

Alanine aminotransferase (ALT) is an enzyme mainly found in the liver. The ALT test measures the level of ALT in the blood. Consistently high levels of ALT can be a sign of liver swelling or injury.

Alkaline Phosphatase (ALP) is an enzyme found in in large amounts in your liver, bile ducts, and other parts of your body. The ALP test measures the level of ALP in your blood. High levels of ALP can be a sign of liver or bile duct damage.

An protein in the blood that is made by the body to fight germs such as viruses or bacteria. Antibodies can be a result of receiving a vaccine or coming into contact with a virus. They protect the body against future infections. An antibody is a protein in the blood that is made by the body to fight germs such as viruses or bacteria. Antibodies can be a result of receiving a vaccine or coming into contact with a virus. They protect the body against future infections.

Ascites is the build up of fluid in the abdomen that can occur with liver failure, cirrhosis and liver cancer.

Aspartate Transaminase (AST) is an enzyme found in large amounts in the liver and other parts of the body. The AST test measures the level of AST in the blood. High levels of AST can be a sign of liver damage.

Autoimmune is an immune response by the body against its own tissue, cells, or molecules. In people with autoimmune disease, their immune system may attack the same cells that it is supposed to protect.

Autoimmune hepatitis is a chronic (long-term) liver disease in which the immune system attacks the liver.

Azotemia is a medical condition characterized by abnormally high levels of nitrogen-containing compounds (such as urea, creatinine, various body waste compounds, and other nitrogen-rich compounds) in the blood. It is largely related to insufficient or dysfunctional filtering of blood by the kidneys. It can lead to uremia and acute kidney injury (kidney failure) if not controlled.

Bile is a liquid made in the liver that helps break down fats and other nutrients.

Bile ducts are tubes that drain the bile from the liver into the intestine.

Biliary atresia is a rare disease of the bile ducts that affects infants. In babies with biliary atresia, the bile ducts become blocked soon after birth.

Cholesterol is a type of fat found in blood.

Cirrhosis is extensive scarring of the liver — hard scar tissue replaces soft healthy tissue. Severe scarring of the liver can prevent the liver from functioning well.

clinical trial is a medical research study conducted to find answers to health questions. Clinical trials often are conducted to evaluate new medications, combination of medications, or new ways to use current treatments. Also, clinical trials are conducted to evaluate new tests, equipment, and procedures for diagnosing and detecting health conditions and to find vaccines to prevent illnesses.

A CT scan is an imaging test that uses x-rays to get detailed pictures of the body.

Crohn’s disease is a type of inflammatory bowel disease (IBD). It causes inflammation of your digestive tract, which can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition. Inflammation caused by Crohn’s disease can involve different areas of the digestive tract in different people.

Creatinine is a breakdown product of creatine phosphate in muscle, and is usually produced at a fairly constant rate by the body (depending on muscle mass).

Diabetes is a condition that occurs when the body cannot use glucose (a type of sugar) normally.

In medicine, dialysis is the process of removing excess water, solutes, and toxins from the blood in people whose kidneys can no longer perform these functions naturally. This is referred to as renal replacement therapy.

Dialysis is used in patients with rapidly developing loss of kidney function, called acute kidney injury (previously called acute renal failure), or slowly worsening kidney function, called Stage 5 chronic kidney disease, (previously called chronic kidney failure and end-stage renal disease and end-stage kidney disease).

Dialysis is used as a temporary measure in either acute kidney injury or in those awaiting kidney transplant and as a permanent measure in those for whom a transplant is not indicated or not possible.

A diuretic is any substance that promotes diuresis (increased urination and the physiologic process that produces such an increase involving extra urine production in the kidneys as part of the body’s homeostatic maintenance of fluid balance), the increased production of urine. This includes forced diuresis. There are several categories of diuretics. All diuretics increase the excretion of water from bodies, although each class does so in a distinct way. Alternatively, an antidiuretic, such as vasopressin (antidiuretic hormone), is an agent or drug which reduces the excretion of water in urine.

Edema is the build up of fluid in the legs that can occur due to liver failure, cirrhosis, and liver cancer.

Endometriosis is an often painful disorder in which tissue similar to the tissue that normally lines the inside of your uterus — the endometrium — grows outside your uterus. Endometriosis most commonly involves your ovaries, fallopian tubes and the tissue lining your pelvis.

Enzymes are protein cells that help important chemical reactions to occur in the body.

See nonalcoholic fatty liver disease.

Fibromyalgia is a disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory and mood issues. Researchers believe that fibromyalgia amplifies painful sensations by affecting the way your brain and spinal cord process painful and nonpainful signals.

Fibrosis is the initial scarring of the liver.

gastroenterologist is a doctor who specializes in the study of digestive organs including the liver.

Genetic refers to something that is related, caused by or affected by genes.

hepatitis C genotype is the genetic makeup of a cell, an organism, or an individual. In the study of liver diseases, the term genotype is used often to describe different strains of hepatitis C virus.

Guillain-Barre syndrome is a rare disorder in which your body’s immune system attacks your nerves. Weakness and tingling in your extremities are usually the first symptoms.

Heme or haem is a substance precursive to hemoglobin, which is necessary to bind oxygen in the bloodstream. Haem is biosynthesized in both the bone marrow and the liver.

Hemochromatosis is a genetic condition in which the body stores too much iron and the iron builds up in the liver.

Hemodialysis, also spelled haemodialysis, or simply dialysis, is a process of purifying the blood of a person whose kidneys are not working normally. This type of dialysis achieves the extracorporeal removal of waste products such as creatinine and urea and free water from the blood when the kidneys are in a state of kidney failure. Hemodialysis is one of three renal replacement therapies (the other two being kidney transplant and peritoneal dialysis). An alternative method for extracorporeal separation of blood components such as plasma or cells is apheresis.

HE is a condition that occurs in people with advanced cirrhosis or severe liver damage. The damaged liver cannot remove the toxins (ammonia) that a healthy liver normally would. These toxins then travel through your body until they reach your brain. They can then affect the brain and cause HE.

Hepatitis means “inflammation of the liver”.

Hepatitis A is a liver disease caused by the hepatitis B and hepatitis C, it does not become chronic (long-term). The hepatitis A virus (HAV). HAV causes the liver to swell and prevents it from working well. HAV is passed from person to person through fecal matter. Most often it is transmitted because of poor hand washing after using the bathroom or changing a diaper, or before preparing and eating food. Unlike hepatitis B and hepatitis C, it does not become chronic (long-term).

Hepatitis B is a liver disease caused by the hepatitis B virus (HBV). HBV causes the liver to swell and prevents it from working well. HBV is passed from person to person through bodily fluids such as blood, semen, or vaginal secretions. Most often it is transmitted through sexual contact or from an infected mother to her infant during birth.

Hepatitis C is a liver disease caused by the hepatitis C virus (HCV). HCV causes the liver to swell and prevents it from working well. HCV is passed from person to person by blood. It is most often transmitted when a person’s blood comes into direct contact with infected blood.

See liver cancer.

hepatologist is a doctor who specializes in the study of the liver.

Hepatorenal syndrome (often abbreviated HRS) is a life-threatening medical condition that consists of rapid deterioration in kidney function in individuals with cirrhosis or fulminant liver failure. HRS is usually fatal unless a liver transplant is performed, although various treatments, such as dialysis, can prevent advancement of the condition.

HRS can affect individuals with cirrhosis, severe alcoholic hepatitis, or liver failure, and usually occurs when liver function deteriorates rapidly because of a sudden insult such as an infection, bleeding in the gastrointestinal tract, or overuse of diuretic medications. HRS is a relatively common complication of cirrhosis, occurring in 18% of people within one year of their diagnosis, and in 39% within five years of their diagnosis. Deteriorating liver function is believed to cause changes in the circulation that supplies the intestines, altering blood flow and blood vessel tone in the kidneys. The kidney failure of HRS is a consequence of these changes in blood flow, rather than direct damage to the kidney. The diagnosis of hepatorenal syndrome is based on laboratory tests of individuals susceptible to the condition. Two forms of hepatorenal syndrome have been defined: Type 1 HRS entails a rapidly progressive decline in kidney function, while type 2 HRS is associated with ascites (fluid accumulation in the abdomen) that does not improve with standard diuretic medications.

The risk of death in hepatorenal syndrome is very high; the mortality of individuals with type 1 HRS is over 50% over the short term, as determined by historical case series. The only long-term treatment option for the condition is liver transplantation. While awaiting transplantation, people with HRS often receive other treatments that improve the abnormalities in blood vessel tone, including supportive care with medications, or the insertion of a transjugular intrahepatic portosystemic shunt (TIPS), which is a small shunt placed to reduce blood pressure in the portal vein. Some patients may require hemodialysis to support kidney function, or a newer technique called liver dialysis which uses a dialysis circuit with albumin-bound membranes to bind and remove toxins normally cleared by the liver, providing a means of extracorporeal liver support until transplantation can be performed.

Hereditary coproporphyria (HCP) is a rare inherited form of liver (hepatic) porphyria, characterized by neurological symptoms in the form of episodes (acute attacks) of stomach pain, nausea, vomiting, weakness, numbness, and pain in the hands and feet (neuropathy).

Interferon is a protein used by the body to fight infection. It is prescribed as an injected medication for people with hepatitis B or hepatitis C.

Irritable bowel syndrome (IBS) is a common disorder that affects the large intestine. Signs and symptoms include cramping, abdominal pain, bloating, gas, and diarrhea or constipation, or both. IBS is a chronic condition that you’ll need to manage long term.

Jaundice is the yellowing of the skin and white part of the eyes.

The liver is the second largest organ in your body. It processes what you eat and drink into energy and nutrients your body can use. The liver also removes harmful substances from your blood.

liver biopsy is a medical procedure used to remove a small piece of liver tissue that is studied in the lab to determine the liver’s condition.

Liver cancer is the growth and spread of unhealthy cells in the liver.

Liver cysts are abnormal sacs filled with fluid in the liver.

Liver failure is the inability of the liver to function and perform its jobs.

Liver function tests help check the liver’s health and detect liver damage. These blood tests measure the levels of certain proteins and enzymes in the blood.

liver transplant is the process of replacing a sick liver with a donated, healthy liver.

living-related liver transplantation is the transplantation of a portion of a healthy person’s liver to a person with advanced liver damage.

A MRI scan uses magnetic waves to obtain images of the liver or other organs.

Nephrotoxicity is toxicity in the kidneys. It is a poisonous effect of some substances, both toxic chemicals and medications, on renal function. There are various forms, and some drugs may affect renal function in more than one way. Nephrotoxins are substances displaying nephrotoxicity.

Nephrotoxicity should not be confused with the fact that some medications have a predominantly renal excretion and need their dose adjusted for the decreased renal function (e.g., heparin).

The nephrotoxic effect of most drugs is more profound in patients already suffering from kidney failure.

Nonalcoholic fatty liver disease (NAFLD) is the build up of extra fat in liver cells that is not caused by alcohol.

Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease that causes the liver to swell and become damaged.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a drug class that reduce pain, decrease fever, prevent blood clots and, in higher doses, decrease inflammation. Side effects depend on the specific drug, but largely include an increased risk of gastrointestinal ulcers and bleeds, heart attack and kidney disease.

Porphobilinogen is an organic compound that occurs in living organisms as an intermediate in the biosynthesis of porphyrins, which include critical substances like hemoglobin and chlorophyll. The name is often abbreviated PBG.

Porphyria refers to a group of diseases that affect fewer than 200,000 people.  Acute Hepatic Porphyria (AHP) refers to a family of rare genetic diseases characterized by potentially life-threatening attacks and, for some people, chronic (ongoing and sometimes lifelong) pain and other symptoms that interfere in their ability to live normal lives.

There are four types of AHP:

  • Acute Intermittent Porphyria (AIP – makes up 80% of all cases)
  • Variegate Porphyria (VP)
  • Hereditary Coproporphyia (HCP)
  • ALAD Deficiency Porphyria (ADP)

AHP is a hereditary disease, meaning that it can be passed from parents to children.  This can occur if either one or both parents carry the defective gene, depending on the AHP type. Men and women inherit the disease equally as often; however, women tend to suffer symptoms more often than men.

Porphyrins are a group of heterocyclic macrocycle organic compounds, composed of four modified pyrrole subunits interconnected at their α carbon atoms via methine bridges (=CH−). The parent of porphyrin is porphine, a rare chemical compound of exclusively theoretical interest. Substituted porphines are called porphyrins. With a total of 26 π-electrons, of which 18 π-electrons form a planar, continuous cycle, the porphyrin ring structure is often described as aromatic. One result of the large conjugated system is that porphyrins typically absorb strongly in the visible region of the electromagnetic spectrum, i.e. they are deeply colored. The name “porphyrin” derives from the Greek word (porphyra), meaning purple.

Metal complexes derived from porphyrins occur naturally. One of the best-known families of porphyrin complexes is heme, the pigment in red blood cells, a cofactor of the protein hemoglobin.

Portal hypertension is hypertension (high blood pressure) in the hepatic portal system – made up of the portal vein and its branches, that drain from most of the intestine to the liver. Portal hypertension is defined as a hepatic venous pressure gradient. Cirrhosis (a form of chronic liver failure) is the most common cause of portal hypertension; other, less frequent causes are therefore grouped as non-cirrhotic portal hypertension. When it becomes severe enough to cause symptoms or complications, treatment may be given to decrease portal hypertension itself or to manage its complications.

Primary Biliary Cholangitis (PBC) is a long-term liver disease that slowly destroys bile ducts in the liver.

Primary sclerosing cholangitis (PSC) is a long-term liver disease that slowly damages the bile ducts in the liver.

Proteins are large molecules that make sure the body’s organs function properly.

Ribavirin is an oral medication that is prescribed together with interferon for some people with hepatitis C.

Splenomegaly is an enlargement of the spleen. The spleen usually lies in the left upper quadrant (LUQ) of the human abdomen. Splenomegaly is one of the four cardinal signs of hypersplenism which include: some reduction in number of circulating blood cells affecting granulocytes, erythrocytes or platelets in any combination; a compensatory proliferative response in the bone marrow; and the potential for correction of these abnormalities by splenectomy. Splenomegaly is usually associated with increased workload (such as in hemolytic anemias), which suggests that it is a response to hyperfunction. It is therefore not surprising that splenomegaly is associated with any disease process that involves abnormal red blood cells being destroyed in the spleen. Other common causes include congestion due to portal hypertension and infiltration by leukemias and lymphomas. Thus, the finding of an enlarged spleen, along with caput medusae, is an important sign of portal hypertension.

Spontaneous bacterial peritonitis (SBP) is the development of a bacterial infection in the peritoneum, despite the absence of an obvious source for the infection. It is specifically an infection of the ascitic fluid – an increased volume of peritoneal fluid. Ascites is most commonly a complication of cirrhosis of the liver. It can also occur in patients with nephrotic syndrome. SBP has a high mortality rate.

Steroids are medications prescribed to treat diseases caused by overactivity of the immune system such as autoimmune liver disease.

Sustained virologic response (SVR) is a person’s successful response to antiviral medications when a virus is not present in the blood six months after treatment is completed.

Triglycerides are a type of fat found in blood

tumor is an abnormal growth of cells that form a lump.

An ultrasound is an imaging technique that uses waves to see inside views of the body.

The urinary system, also known as the renal system or urinary tract, consists of the kidneys, ureters, bladder, and the urethra. The purpose of the urinary system is to eliminate waste from the body, regulate blood volume and blood pressure, control levels of electrolytes and metabolites, and regulate blood pH. The urinary tract is the body’s drainage system for the eventual removal of urine. The kidneys have an extensive blood supply via the renal arteries which leave the kidneys via the renal vein. Each kidney consists of functional units called nephrons. Following filtration of blood and further processing, wastes (in the form of urine) exit the kidney via the ureters, tubes made of smooth muscle fibers that propel urine towards the urinary bladder, where it is stored and subsequently expelled from the body by urination (voiding). The female and male urinary system are very similar, differing only in the length of the urethra.

A vaccine is a medication that stimulates the production of antibodies to protect against a specific disease.

Variegate Porphyria is a rare genetic metabolic disorder characterized by deficient function of the enzyme protoporphyrinogen oxidase (PPO or PPOX). This deficiency is caused by heterozygous mutations in the PPOX gene and leads to the accumulation of certain chemicals called porphyrins and toxic porphyrin precursors in the body, which, in turn, can potentially result in a variety of symptoms. Specific symptoms can vary greatly from one person to another. Some affected individuals present with skin symptoms, some with neurological symptoms and some with both. Blistering and fragility of sun-exposed skin are the most common skin (cutaneous) symptoms. Common neurological symptoms include abdominal pain, nausea, vomiting, constipation, extremity pain and weakness, anxiety, restlessness and convulsions. Many different PPOX mutations have been identified in different families with Variegate Porphyria. The genetic mutation in a family is inherited as an autosomal dominant trait, but many individuals who inherit a PPOX mutation do not develop any symptoms (asymptomatic).

Viral hepatitis is liver inflammation due to a viral infection. It may present in acute form as a recent infection with relatively rapid onset, or in chronic form.

The most common causes of viral hepatitis are the five unrelated hepatotropic viruses hepatitis A, B, C, D, and E. Other viruses can also cause liver inflammation, including cytomegalovirus, Epstein-Barr virus, and yellow fever. There also have been scores of recorded cases of viral hepatitis caused by herpes simplex virus.

viral load is the amount of a virus, such as hepatitis B or hepatitis C virus, in the blood.

Wilson disease is a genetic condition in which the body stores too much copper and the copper builds up in the liver.

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