Non-alcoholic steatohepatitis (NASH) is a growing public health issue, affecting an estimated three to five percent of the global adult population.[i] It typically progresses slowly with few – if any – obvious or visible symptoms[ii],[iii], making it a largely unrecognized and underdiagnosed disease. Many physicians are not intimately familiar with NASH, and, for many patients, their diagnosis is the first time they’ve heard the term.

NASH, by definition, is a serious, progressive form of non-alcoholic fatty liver disease (NAFLD). NASH develops in about 20% of NAFLD patients when excess of liver fat is accompanied by cell ballooning, inflammation and cell damage.2,[iv] Risk factors, such as obesity, type 2 diabetes, insulin resistance, metabolic syndrome, and a genetic predisposition, can lead to metabolic changes in the liver, causing excessive fat accumulation and putting patients at risk for developing NASH.[v],[vi]

Learn more about NASH – its causes and its impact inside the body – in the video below.

Pfizer is committed to advancing the science and understanding of NASH and to uncover potential treatments for people impacted by this serious condition.


[i] Chalasani, N., et al. The diagnosis and management of non-alcoholic fatty liver disease: practice Guideline by the American Association for the Study of Liver Diseases, American College of Gastroenterology, and the American Gastroenterological Association. June 2012.

[ii] Perumpail, Brandon J et al. “Clinical epidemiology and disease burden of nonalcoholic fatty liver disease.” World journal of gastroenterology vol. 23,47 (2017): 8263-8276. doi:10.3748/wjg.v23.i47.8263

[iii] Sanyal, AJ et al. The Natural History of Advanced Fibrosis Due to Nonalcoholic Steatohepatitis: Data From the Simtuzumab Trials. Hepatology. Apr. 2019. doi: 10.1002/hep.30664.

[iv] “Definition and Facts of NAFLD and NASH.” National Institute of Diabetes and Digestive and Kidney Diseases. Updated November 2016,

[v] Machado and Cortez-Pinto. Non-alcoholic fatty liver disease: What the clinician needs to know. World J Gastroenterol vol. 20(36): 12956–12980, Sep. 2014,  

[vi] Chalasani, Naga et al. “The Diagnosis and Management of Non-alcoholic Fatty Liver Disease: Practice Guideline by the American Gastroenterological Association, American Association for the Study of Liver Diseases, and American College of Gastroenterology.” Gastroenterology. 2012; 142: 7: 1592-1609,