Nonalcoholic fatty liver disease is the leading cause of chronic liver disease in the United States; alcoholic liver disease is another cause, affecting more than 15 million adults nationwide, according to WebMD. Other causes of liver disease include viral infections and genetic disorders, explains Mayo Clinic.
Nonalcoholic fatty liver disease and fatty liver disease affect up to 20 percent of the adult population. Nonalcoholic fatty liver disease most frequently develops in middle-aged adults who are overweight and have prediabetes or elevated levels of triglycerides and cholesterol. It also tends to run in families, according to WebMD.
Viral infections by hepatitis type A, B or C can also increase the development of liver disease. These are most commonly spread by blood, sexual transmission, food and water or close contact with infected individuals. Genetic diseases such as hemochromatosis, hyperoxaluria and Wilson’s disease all affect the liver and can cause significant damage to the liver over time, leading to liver disease, explains Mayo Clinic.
The liver is responsible for many important functions in the body, which is why so many symptoms are associated with liver disease. These symptoms include nausea, vomiting, pain in the right upper abdominal quadrant, yellowing of the skin, fatigue and weight loss. Symptoms typically do not present until about 75 percent of the liver is affected, according to MedicineNet.