THe liver is responsible for many critical functions within the body and should it become diseased or injured, the loss of those functions can cause significant damages to the body.  The liver is the largest solid organ in the body and is also considered a gland because among its many functions, it makes and secretes bile.  
Symptoms: nausea, vomiting, right upper belly pain, jaundice, fatigue, weakness, and weight loss.
The liver cells have two different sources of blood supply.  The hepatic artery supplies oxygen rich blood that is pumped from the heart, while the portal vein supplies nutrients from the intestine and spleen.  Normally veins return blood from the body to the heart, but the portal vein allow chemicals from the digestive tract to enter the liver for "detoxification" amd filtering prior to entering the general circulation.  The portal vein also efficiently delivers the chemicals and proteins that liver cells need to produce the proteins, cholestrol, and glycogen required for normal body activities.  As part of its function, the liver makes bile, a fluid containg water, chemicals, and acids.  Bile is stored in the gallbladder.  The liver is the only organ in the body that can easily replace damged cells, buut if not enough cells are lost the liver begins to poison the body..  Functions of the liver: production of bile, storing of extra sugar for energy, production of blood clotting factors, production of amino acids, processing and storage of iron necessary for red blood cell production, manufacture of cholestrol and oter chemicals requird for fat transport, converts waste products tobe excreted, and metabolizing medicatoins.
  • Cirrhosis: permanent scarring of the liver.  The normal liver cells are replaced by scar tissue that cannot perform any liver function.
The causes of liver disease (alcohol and cirrhosis)?
The liver can be damaged in a variety of ways: cells can become inflammed, bile flow can be obstructed, cholesterol can accumulate, blood flow to the liver may be compromied, and liver tissue can be damaged by chemicals and minerals(cancer cells).  Alcohol abuse is highly toxic to liver cells and can cause inflammation.  Cirrhosis is the late-stage of liver disease.  Scarring of the liver and loss of functioning liver cells cause the liver to fail.  SIgnificant amounts of liver cells need to be damaged before the hole organ fails to function.  
Drug-Induced Liver Disease;  There are numerous medications that may cause liiver disease.  Acetaminophen (Tylenol), medications to control elevated blood levels of cholestrol, Niacin/ another cholestrol controlling medication which is related to the dose taken, antibiotics (nitrofurantoin, Macrodantin, Amoxicillin, Augmentin, Methotrexate, and Antabuse.  Stay Away from Herbal remedies until side effects are known (Vitamin A, Kava, Ma0huang, comfrey, and Wild Mushrooms.
Hepatitis and Other Causes:   Hepatitis A (viral and Vaccine can prevent), Hepatitis B (bodily fluids, Hep B vaccine can prevent), Hepatitis C (bodily fluids, No vaccine), Non-Alcoholic Liver Disease( fatty-liver, fat accumulation causes failure), Hemochromatosis (iron overload, excess iron can accumulate in the liver, pancreas, and heart:leads to cirrhosis, cancer, and liver failure, INHERITED)  WIlson's DIsease(INHERITED, cannot metabolize Copper. leads to cirrhosis and failure), Gilberts Disease(abnormal buildup of bilirubin in liver).  
Cancer and others:   Primary cancers of the liver arise from liver structures and cells.  COmmon cncers that spread to the liver begin in the lung, breast, large intestine, stomach and pancreas.  Leukemia and Hodgkins may also involve the liver.  Budd Chari syndrome( blood clots form in the hepatic vein and prvent blood from leaving the liver. This increases pressure within the blood vessels and the portal vein (causes liver cells to die).)  COngestive Heart Failure (poor heart function causes fluid and blood back up in the large veins of the body cn cause liver swelling and inflammation.) GallStones (obstruction of the ducts that drains bile from the liver.  Hepatic Encephalopathy (increase ammonia levels due to livers inability to process and metabolize proteins in the diet, causes Confusion, Lethargy, and Coma).  Abnormal Bleeding (liver function to make blood clotting factors is compromised), Protein Manufacturing (proteins made in the liver are the building blocks for body function). Portal Hypertension (incresed pressure within the blood vessels in the liver and affect blood flow to other organs).  
Symptoms for Liver Disease:  nausea, vomiting, upper right belly pain, jaundice, ftigue, weakness, weightloss, easy bruising, itching, gynocomastia, impotence, confusion, ascites, muscle wasting, and swollen veins around stomach and esophagus.  
When to see your doctor:  Jaundice or yellow skin, constant fever, vomiting, and abdominal pain, and Acetaminophen or Tylenol overdose.  
Diagnosing Liver Disease: history and physical exam, symptoms, risk factors, history of alcohol?, Blood test:  AST, ALT, GGT, bilirubin, protein and albumin levels, CBC, INR, lipase, electrolytes, ammonia, imaging studies and Liver Biopsy..
Treatments for Liver DIsease:  hep A (care and hydration), Gallstones (surgery), Low Sodium Diet and Water pills, paracentesis, and Liver Transplant
Preventing Liver Disease:  Low-Sodium Diet, Alcohol in moderation, minimize risk of bodily fluid exposure, Vaccinations, Screenings, weight control and routine exercise program.  
 
TAKE CARE OF YOUR LIVER!  IT MIGHT ONLY HAVE ONE CHANCE!
 
ADDITIONAL INFORMATION:
www.heart.org
www.americanliverdiseasefoundation
www.vanderbilt medical center