The Human Liver: Function and Disease States

The human liver is an amazing work of art. It is a large organ located just below the diaphragm on the upper right side of the abdomen, and consists of two parts, the right lobe and a smaller left lobe. Your liver performs many jobs to help keep you healthy. When you take prescription or over-the-counter medications, your liver breaks them down so that they can eventually be cleared from your body. Your liver also clears alcohol and environmental toxins from your blood. It produces bile which aids in the digestion of fatty foods. Excess carbohydrates are stored in your liver as glycogen which can be later released to provide needed energy. The blood clotting that is part of the wound-healing process requires certain proteins. Your liver synthesizes these proteins.

If your doctor suspects that something is wrong with your liver, he or she may order liver function tests. Doctors use the results of these tests to help determine if your liver has become diseased or damaged. According to the Mayo Clinic, liver function tests are blood tests to determine the level of certain proteins and liver enzymes. The tests most commonly measure the blood levels of the enzymes alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP). Normally, these enzymes are in liver cells and at low levels in the blood. If, however, your liver becomes diseased or damaged, these enzymes leak into the blood and higher-than-normal levels can be detected.

In addition to liver enzymes, there are other blood components that can indicate damage to the liver. Albumin is a protein synthesized in the liver. The "albumin and total protein" test indicates how well your liver is making the proteins that you need to be healthy. Lower-than-normal blood levels could signal a possible liver problem. Bilirubin is a substance that results when the liver breaks down worn-out red blood cells. Under normal circumstances, your liver removes bilirubin from the blood, and it eventually leaves your body in the feces. Higher-than-normal blood levels of bilirubin usually indicates that the liver has become diseased or damaged, and leads to the yellowing of the skin and eyes referred to as jaundice.

Alcoholic Liver Disease--Chronic consumption of excessive amounts of alcoholic beverages can lead to alcoholic liver disease. According to the National Institute on Alcohol Abuse and Alcoholism, this disease has three stages. The first stage, alcoholic fatty liver, is characterized by the deposition of fatty deposits in the liver and can be reversed if you stop drinking. The second stage is called alcoholic hepatitis, and in this stage the liver has become inflammed. This condition can be fatal, but it is still possible to reverse it by abstaining from alcohol completely. Cirrhosis is the third stage, and it is characterized by scarring of the liver and the closing of blood vessels. This condition is progressive and fatal.

Hepatitis--This is an inflammation of the liver and is caused most commonly by the hepatitis A, B and C viruses, according to the Centers for Disease Control and Prevention (CDC). You get hepatitis A by consuming food or drink contaminated with tiny amounts of fecal matter from an infected person. The condition lasts anywhere from a few weeks to several months. You will recover without special treatment, and there is usually no permanent damage to your liver. Symptoms may include fever, fatigue, loss of appetite, dark urine, clay-colored stools and jaundice. There is a vaccine against hepatitis A. Hepatitis B is contracted by exposure to the blood, semen or other body fluid of an infected person. This exposure usually comes from having sexual contact or from sharing contaminated needles to inject illegal drugs. Hepatitis B can be an acute, short-term illness or it can be a chronic disease leading to long-term negative health consequences and even death. The CDC recommends all infants get the hepatitis B vaccine as well as older children and adults at risk for contracting the disease. Hepatitis C is usually contracted by sharing needles or other devices to inject illegal drugs. In most cases, hepatitis C is a chronic illness that leads to serious liver damage such as cirrhosis and liver cancer. There is no vaccine available for hepatitis C.

Liver Cancer--Cancer that starts in the liver is called hepatocellular carcinoma. According to PubMed Health, this disease usually strikes people over 50 and is more common in Africa and Asia than in North and South America. The cause is frequently the cirrhosis that follows from alcohol abuse and hepatitis B or C. Symptoms may include abdominal pain or tenderness, enlarged abdomen and jaundice. Doctors may treat hepatocellular carcinoma with surgery to remove the tumors, chemotherapy or radiation, but the prognosis for recovery is very poor.

This hub has been written for the sole purpose of providing information to the reader. It is not intended to be a source of any kind of medical advice or instruction, and it should not be used in the diagnosis of any illness, disease or condition. You should consult your doctor if you have questions about a specific medical problem.