When a person has fatty liver, over 5 or 10 percent of the weight of his liver consists of fat. Fatty liver is not necessarily dangerous as long as damage or inflammation do not occur, explains WebMD.
A person with a fatty liver may also have alcoholic or nonalcoholic liver disease in addition to fatty liver. Either of those diseases can cause severe consequences, as stated by WebMD.
Nonalcoholic fatty liver disease, or NAFLD, is the leading cause of chronic liver disease in the United States. Not everyone with fatty liver develops this disease, but those who do have an elevated risk of heart disease. Sometimes this disease becomes nonalcoholic steatohepatisis, or NASH. This can lead to permanent damage to the liver over time, as the organ gets bigger and scar tissue replaces healthy cells, in a condition known as cirrhosis. Eventually, the liver stops working correctly, and organ failure, liver cancer and death can result. NASH is a major cause of cirrhosis, notes WebMD.
Alcoholic liver disease is the result of overuse of alcohol over time. Over 15 million Americans drink alcohol to excess, and over 90 percent of them end up with fatty liver as a result. Genetics and heredity can influence alcoholic liver disease, but so can drinking habits. People who are obese, have too much iron in their system or who have hepatitis C have a higher chance of developing ALD, reports WebMD.