1. Liver injury: Hepatocellular pattern (AST/ALT up more than alk phos)
DDx: viral, etoh, steatohepatitis, autoimmune, cirrhosis, drugs
>1000: acute viral, ischemia, drugs/toxins, autoimmune, acute bile duct obstruction, acute budd chiari
<1000: viral hep, alcohol, NAFLD, meds/toxins, cirrhosis, autoimmune, hemochromatosis, wilson's, a1-antitrypsin deficiency.
2. Liver injury: Cholestatic pattern (alk phos up more than ast/alt):
Us/CT/MRCP : biliary ducts normal = intrahepatic, dilated= extrahepatic
extrahepatic:  obstruction
intrahepatic: viral/etoh hepatitis, cirrhosis, drugs/toxins, sepsis, tpn, postop, infiltrations (amyloid sarcoid) , PSC (30-90% p-ANCA+), PBC (95% mitochondrial ab)
3. Miscellaneous liver facts: 
- Jaundice when Tbili >2.5-3. scleral icterus visible before skin jaunidce
Hepatomegaly: "I think I feel the liver edge" physical exam finding has a LR+ 233 for "palpable liver edge". LOL basically if you think you can feel the liver.. you're correct.
- However, palpable liver edge on exam has LR 1.9 for actual hepatomegaly-- many things can cause the liver to be pushed down, rather than enlarged.
4. Hepatitis 
- Hep A: 20-50% of cases of viral hepatitis, Dx: Hep A serologies
- Hep B:
<1% progression to chronic if acquired as immunocompetent adult
>90% progression to chronic if acquired perinatally-- which is the primary means of acquisition in china.
20% progression to chronic if acquired in childhood
Dx: acutely, HbSAg. Don't need E, bc acute hep B is (by definition) infective. The E antigen is good for determining infectivity in chronic hep B.
5. Things that can cause hypertriglyceridemia: 
- Alcohol
- Uncontrolled diabetes
- Nephrotic syndrome
- Congenital (LDLR deficiency, lipoprotein lipase deficiency, familial hyperlipidemias)
- Drugs (beta-blockers, thiazide diuretics, accutane, estrogens, protease inhibitors, propofol)
- Lupus
- Hypothyroidism.
6. Steatosis 
-early: asymptomatic
-hepatomegaly
-dx on u/s
-potentiates liver damage from other insults
-found in 90% of people drinking > 6 drinks a day
7. EtOH steatohepatitis
- Affects 15-30% of people w alcoholic liver disease
- malnutrition in 90%, cirrhosis in > 50%
- 3 mo mortality: 15% mild, 55% severe
Dx: transaminases high but <6-7x of normal; AST:ALT ratio >2 in 70-80% cases. Liver biopsy is the gold standard for diagnosis. Imaging rules out other diagnoses.
Dx criteria in RCTs studying this:
-history of excessive alcohol, Tbili > 4.5 ast <500, alt <300, exclude other causes (viral, autoimmune, obstructive, cancer)
8. Pancreatic cancer 
>90% ductal
70-80% in head
abominal pain 80%, weight loss, jaundice
- If you suspect pancreatic mass, get an ultrasound:
- If you do an u/s and see a pancreas mass= get a triphasic pancreas multidetector CT
- If us/s shows no mass - MRCP (noninvasive, good sens/spec) > EUS (requires endoscopy, fewer comp than ERCP) > ERCP is invasive (low sens for panc cancer, increases risk of pancreatitis)
9. Things that cause mild transaminitis (<3x nl)
-acetaminophen
-statin
-NAFLD
-chronic viral hepatitis
-a little bit of drinking
-EBV/CMV/VZV/HIV
-hyperthyroidism
-muscle disease (ast only)
-strenuous exercise (alt only)
more rare causes:
-autoimmune, hemochromatosis, a1-antitrypsin, wilsons, celiac's
10. NAFLD 
- excessive fatty liver without a secondary cause, like alcohol, wilsons, jejunal bypass, tpn, protein-cal malnutrition, drugs
- prevalence: worldwide 6-33%, US: 46% (hisp > white > black), people with diabetes 69%, bariatric surgery patients 90%
- imaging finds steatosis, but not inflammation
- liver bx is gold standard to figure out inflammation state
- who needs bx: unclear etiology, high risk of NASH/fibrosis. Unfortunately if you do find NASH, there isn't much treatment (control diabetes, lose weight, go on statin, 1 study showing pyoglitazone may help). So weigh the benefit of a certain diagnosis against the cost of subcapsular hematoma/abdominal hemorrhage.