The liver is a large, reddish-brown organ that sits mainly in the upper right portion of the abdomen above the stomach and below the diaphragm. Weighing around 1.3 kg in females and 1.8 kg in males, the liver is the largest solid organ in the body. The liver holds around 13% of the body’s blood supply and performs approximately 500 different functions.
The liver is made up of cells called hepatocytes, which absorb nutrients and detoxify the blood by eliminating harmful substances. The liver is therefore a vital organ for digestion and ridding the body of toxins.
Liver disease can occur as an inherited condition or be caused by various factors that lead to liver damage such as viral infection, alcohol use or obesity. Long-term or chronic liver damage can eventually lead to scarring of the organ, a condition referred to as cirrhosis. Cirrhosis is a non-reversible, dangerous condition that can lead to liver failure.
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Symptoms of liver disease
Over a hundred different types of liver disease are currently known to exist and symptoms can vary widely depending on whether a patient has hepatitis, alcoholic liver disease, fatty liver disease or cirrhosis, for example.
Furthermore, symptoms are not always obvious in the early stages of liver disease. Symptoms can be mild and non-specific such as a loss of appetite, fatigue, general malaise, nausea and vomiting or weight loss. Such symptoms may therefore easily be overlooked in a patient with early-stage disease.
As liver disease progresses, however, some key clinical features that may manifest include:
Pain in the right upper abdomen
Pain and discomfort may be felt in the upper right side of the abdomen where the liver is located. Pain may be caused by the liver growing in size due to the accumulation of fat, acute inflammation or any injury that can expand and stretch the sensitive membrane covering the liver.
Hepatomegaly
Liver disease can disrupt blood flow in the liver or cause tumors (benign or malignant) to develop, which adds to the mass of the liver. Some of the most common causes of hepatomegaly are metastatic cancer, hepatomegaly, fatty liver disease and cirrhosis.
Jaundice
Jaundice is indicated by a yellowing of the skin, whites of the eyes and nails. This is caused by the damaged liver failing to adequately process bilirubin, the waste product that occurs when old red blood cells are broken down. An excess of bilirubin accumulates in the blood and deposits in the skin, which causes yellowish discoloration.
Symptoms of liver cirrhosis
In the early stages of cirrhosis, symptoms can again be non-specific and mild. Patients may therefore overlook symptoms and attribute them to other conditions.
The term cirrhosis refers to the formation of scar tissue (fibrosis) in place of liver cells that have died as a result of long-term liver damage. This may have occurred due to excess alcohol intake, viral hepatitis or other factors that lead to toxicity of the liver.
Liver fibrosis is characterized by the presence of irregular tumors or nodules that form across what was originally smooth liver tissue. This scarring leads to the hardening of the liver tissue which prevents blood flow to the liver and affects its function.
As cirrhosis develops gradually and often without any obvious symptoms, the condition may go unnoticed until the damage is severe and likely to lead to liver failure.
Some of the symptoms of liver cirrhosis are described below:
Itching
Also called pruritis, this may be caused by a chemical in the bile that can accumulate in the bloodstream (jaundice). Although pruritis is a common symptom, it is not always present. When this symptom does occur, it can be distressing and even debilitating, causing an intense itch across the entire skin surface.
Bruising easily
Liver damage can prevent the production of the proteins required for blood clotting, which can lead to an increased tendency to bruise or bleed.
Hormone imbalance
A damaged liver may fail to regulate the production and breakdown of hormones. In males, this can lead to enlarged breasts (gynecomastia) and shrunken testicles, while women may find their menstrual cycle is affected.
Spider angiomas
Spider angiomas are small, spider-like capillaries that are visible just underneath the surface of the skin. These occur when a person’s estrogen level is increased, which may happen if the liver is failing to adequately metabolize the hormone. Around 33% of people with cirrhosis develop spider angiomas.
Alcoholic Liver Disease, Animation
Encephalopathy
Hepatic encephalopathy refers to a decline in brain function that occurs as a result of toxic substances accumulating in the brain because the liver is no longer able to effectively eliminate them.
Research has implicated certain substances as causative of hepatic encephalopathy and these include ammonia, free fatty acids, mercaptans and false neurotransmitters.
This complication of cirrhosis can lead to symptoms such as confusion, loss of short-term memory and even loss of consciousness.
Ascites
Ascites refers to the edema or fluid retention that occurs as a result of poor kidney function in cirrhosis. A decline in kidney function leads to the retention of sodium and water.
Portal hypertension
When cirrhosis has led to severe scarring of the liver, blood is prevented from flowing through the organ easily. This causes pressure to build up in the vein that supplies the liver with blood. This is called the portal vein and the increased pressure is referred to as portal hypertension.
As the pressure increases, blood begins to travel along alternative veins present in the esophagus and stomach. These veins are called varices and their walls are fragile and prone to rupture. Hemorrhage of these veins causes internal bleeding and this is often first noticed as hematemesis (the vomiting of blood) or melena (the passing of black and tarry stools).
The rupturing of varices is a serious and life-threatening complication of cirrhosis that requires urgent medical attention.
References
Further Reading
Exploring mouse models for studying liver fibrosis regression