Alanine Aminotransferase


Core Lab Study


To assess liver function related to liver disease and/or damage; differentiate between jaundice related to liver disease and jaundice related to RBC hemolysis.

A small group of studies in this manual have been identified as Core Lab Studies. The designation is meant to assist the reader in sorting the basic “always need to know” laboratory studies from the hundreds of other valuable studies found in the manual—a way to begin putting it all together.

Normal, abnormal, or various combinations of core lab study results can indicate that all is well, reveal a problem that requires further investigation with additional testing, signal a positive response to treatment, or suggest that the health status is as expected for the associated situation and time frame.

ALT is included in the liver function test panel (LFTs) and in the comprehensive metabolic panel (CMP). LFTs are used to identify liver disease, assess severity of injury, or monitor disease process and response to treatment. CMPs are used as a general health screen to identify or monitor conditions such as bone disease, diabetes, electrolyte imbalance, hypertension, kidney disease, liver disease, or malnutrition.Patient Preparation
There are no food, fluid, activity, or medication restrictions unless by medical direction.

Normal Findings
Method: Spectrophotometry.

AgeConventional and SI Units
Newborn7–41 units/L
Child, Adult
  Male19–36 units/L
  Female24–36 units/L
Greater than 90 yr
  Male6–38 units/L
  Female5–24 units/L
Values may be slightly elevated in older adults due to the effects of medications and the presence of multiple chronic or acute diseases with or without muted symptoms.

Critical Findings and Potential Interventions


(Study type: Blood collected in a gold-, red-, red/gray-, or green-top [heparin] tube; related body system: Digestive system.)

ALT is an enzyme produced by the liver. The aminotransferases (ALT and AST) are indicators of liver injury, evidenced by increased serum levels related to enzymes leaking from damaged cells into the circulating blood. The highest concentration of ALT is found in liver cells (hepatocytes); smaller amounts are found in the heart, kidneys, pancreas, spleen, skeletal muscle, and RBCs. ALT is a sensitive and more specific indicator of liver disease than AST.

Examples of Possible Patterns Between ALT Levels and Other Core LFT Levels in Specific Hepatic Conditions
DiagnosisALT Level (Other Core LFTs)
Cholestasis↑ Normal to Mild (Alb ↓, ALP ↑↑↑, AST ↑, TBil ↑)
Cirrhosis↑ to ↑↑ Normal to Mild or Moderate (Alb ↓, ALP ↑ to ↑↑, AST ↑↑↑, TBil ↑)
Hepatitis, viral, acute↑↑↑ Marked (Alb ↓, ALP ↑ to ↑↑, AST ↑↑↑, TBil ↑ to ↑↑)
Hepatitis, toxin or drug related↑↑↑ Marked (Alb ↓, ALP ↑ to ↑↑, AST ↑↑↑, TBil ↑↑)
Infarction, acute necrosis of the liver, or cancer↑↑↑ Marked (Alb ↓, ALP ↑ to ↑↑, AST ↑↑ to ↑↑↑, TBil ↑↑)
Jaundice, hepatic origin↑↑ Mild to Moderate with ALT rising before AST and TBil (Alb ↓, ALP ↑ to ↑↑, AST ↑↑, TBil ↑ to ↑↑)
Relative ALT and TBil levels in non-hepatic jaundice
Jaundice, RBC originALT ↑ Normal to Mild and TBil ↑↑ Mild to Moderate or ↑↑↑ Marked, in proportion to the degree of hemolysis
N = Normal, ↓ Normal to Mild decrease, ↑ Normal to Mild increase, ↑ to ↑↑ Normal to Mild or Moderate, ↑↑ Mild to Moderate, ↑↑↑ Marked. Study levels will vary with degree and progression of liver damage. ALT levels remain elevated longer than AST levels.


  • Differentiate jaundice related to liver disease vs jaundice related to RBC hemolysis.
  • Monitor liver damage resulting from liver disease and infections.
  • Monitor liver damage resulting from hepatotoxic chemicals and drugs.
  • Monitor response to treatment of liver disease, with tissue repair indicated by gradually declining levels.

Interfering Factors

Factors that may alter the results of the study

  • Drugs and other substances that may increase ALT levels include acarbose, ACE inhibitors, acetaminophen (toxic), acetylsalicylic acid, allopurinol, amoxicillin, amiodarone, ampicillin, amytriptyline, ARBs, asparaginase, azathioprine, beta-blockers, baclofen, bupropion, carbamazepine, cephalosporins, chloramphenicol, chlordiazepoxide, chlorpromazine, chlorpropamide, clindamycin, cloxacillin, clopidogrel, codeine, cyproheptadine, cytarabine, danazol, desipramine, dicumarol, doxepin, enflurane, erythromycin, estrogens, ethambutol, ethionamide, ethotoin, ethyl alcohol, fibrates, gentamicin, gold salts, imipramine, isoniazid, ketoconazole, low-molecular-weight heparin, methyl dopa, metaxalone, methotrexate, nafcillin, naladixic acid, nitrofurans, nortriptyline, NSAIDs, omeprazole, oral contraceptives, oxacillin, phenobarbital, phenytoin, probenecid, procainamide, propoxyphene, pyrazinamide, quinidine, rifampin, risperidone, sulfonamides, terbinafine, tetracyclines, trazadone, trimethoprim, valproic acid, verapamil, and zidovudine.
  • Hemolyzed specimens may cause falsely-elevated results.

Potential Medical Diagnosis: Clinical Significance of Results

Increased in

Related to release of ALT from damaged liver, kidney, heart, pancreas, red blood cells, or skeletal muscle cells.

  • AIDS (related to hepatitis B co-infection)
  • Acute autoimmune hepatitis
  • Biliary tract obstruction (passage of stone from common bile duct can produce moderate, transient increase)
  • Budd-Chiari syndrome (acute)
  • Burns (severe)
  • Cirrhosis
  • Fatty liver (e.g., acute fatty liver of pregnancy)
  • HELLP syndrome of pregnancy; variant of pre-eclampsia (hemolysis, elevated liver enzymes, low platelet count)
  • Hepatic cancer
  • Hepatic infarction or necrosis
  • Hepatitis (drug or toxin induced)
  • Hepatitis, viral (acute or reactivation)
  • Infectious mononucleosis
  • Muscle injury from intramuscular injections, trauma, infection, and seizures (recent)
  • Muscular dystrophy
  • Myositis
  • Nonalcoholic fatty liver disease
  • Pancreatitis (acute)
  • Pre-eclampsia
  • Shock (severe)
  • Substance use disorder (alcohol)
  • Wilson disease (acute)

Decreased in

  • Pyridoxal phosphate deficiency (related to a deficiency of pyridoxal phosphate that results in decreased production of ALT)

Nursing Implications, Nursing Process, Clinical Judgement

Potential Nursing Problems Assessment and Nursing Diagnosis

ProblemsSigns and Symptoms
Bleeding, risk (related to altered clotting factors, portal hypertension)Cool extremities, delayed capillary refill, decreased distal pulses, altered mental status, hypotension, tachycardia, decreased level of consciousness. Bruises easily, hematemesis, weakness, shortness of breath, bloody or black stools. PT prolonged greater than 13.5 seconds.
Confusion, risk (related to neurosensory changes associated with cerebral ammonia accumulation related to substance use disorder [alcohol], hepatic metabolic insufficiency, hepatic encephalopathy)Disoriented to person, place, time, and purpose; inability to follow directions or provide an adequate history; delusions; inappropriate behavior; violence that is directed to self or others; inappropriate affect; forgetfulness, anxiety, fearfulness, short attention span; personality changes; mood swings; difficulty or inability to perform mental tasks such as simple math; changed sleep patterns such as confusing day and night to extreme sleepiness; difficult slow or sluggish hand movement, jumbled slurred speech, or inability to perform familiar purposeful actions
Fluid volume (deficit—related to vomiting, decreased intake, compromised kidney function, overly aggressive diuresis)  Decreased urinary output, fatigue, sunken eyes, dark urine, decreased blood pressure, increased heart rate, altered mental status, dehydration, poor skin turgor
  Fluid volume (excess—overload related to overly aggressive fluid resuscitation; ascites related to hypoalbumenia, imbalanced aldosterone, altered [low] serum osmotic pressure)  Fluid resuscitation: edema, shortness of breath, rales, rhonchi, and diluted laboratory values. Abdominal ascites-increasing abdominal girth. Fluid resuscitation and abdominal ascites: increased weight.
Gas exchange, risk (ineffective—related to blood loss secondary to ineffective clotting factors, increased abdominal girth secondary to liver cirrhosis)Orthopnea, dyspnea, shortness of breath at rest or with activity, pallor, shallow respirations, cyanosis, altered blood gas, increasing abdominal girth
Gastrointestinal (related to altered motility, irritation of the GI tract, taste alterations, pancreatic and gastric secretions)Nausea, vomiting, abdominal distention, unexplained weight loss, steatorrhea, diarrhea, visible abdominal distention, ascites, diminished or absent bowel sounds
Nutrition (insufficient—related to metabolic imbalances, excess alcohol use, nausea, malabsorption, anorexia)Increased liver function tests; hyperglycemia with polyuria, weight loss, weakness, nausea, vomiting; hypocalcemia with confusion, intestinal cramping, diarrhea; hypertriglyceridemia; altered thiamine with weakness, confusion
Pain (related to organ inflammation and surrounding tissues, excessive alcohol intake, infection)Emotional symptoms of distress, crying, agitation, facial grimace, moaning, verbalization of pain, rocking motions, irritability, disturbed sleep, diaphoresis, altered blood pressure and heart rate, nausea, vomiting, self-report of pain, upper abdominal and gastric pain after eating fatty foods or alcohol intake with acute pancreatic disease, pain may be decreased or absent in chronic pancreatic disease
Skin, risk (related to elevated serum bilirubin levels and excess bile salt resulting in tissue irritation and histamine release, jaundice associated with liver disease)Reports itchy skin (dermatitis/pruritis); chronic scratching; dry, scaly skin; yellow skin and sclera; visible scratch marks with or without scabbing; rash

Before the Study: Planning and Implementation

Teaching the Patient What to Expect

  • Discuss how this test can assist with evaluation of liver function and help identify liver disease.
  • Explain that a blood sample is needed for the test.

After the Study: Implementation & Evaluation Potential Nursing Actions

Avoiding Complications

  • The patient with cirrhosis should be carefully observed for the development of ascites, in which case fluid and electrolyte balance requires strict attention.

Treatment Considerations

  • Monitor and trend labs: ALT. ALT levels may be lower than expected in liver disease attributable to substance use disorder (alcohol) related to a dietary deficiency of pyridoxyl-5–phosphate, an essential cofactor for ALT synthesis. Compare with LFTs (Alb, ALP, AST, TBil, DBil, TP) or other related studies to track the course of disease and response to treatment. Monitor blood alcohol and ammonia levels. If liver function is significantly damaged, PT will be prolonged and INR increased. Trend PT, INR, H&H, and ABG results.

Bleeding, Risk

  • Complete frequent checks of vitals signs to monitor for changes outside of patient’s baseline.
  • Monitor for bleeding symptoms (stools, emesis, bruising).
  • Monitor for shortness of breath; administer oxygen as ordered.
  • Administer ordered blood and blood products per facility protocol.

Confusion, Risk

  • Observe for altered attention span, inability to give an accurate history, loss of concentration, inability to follow commands, behavior that is inappropriate or violent, inappropriate affect.
  • Institute fall precautions, assist with activity, low bed position, restraints as necessary.
  • Attempt reorientation to person, place, time, and purpose.
  • Administer prescribed medications, lactalose, nonhepatic metabolized sedatives.
  • Encourage family to assist in providing an emotionally stable environment.

Fluid Volume, Deficit

  • Facilitate management of fluid volume deficit.
  • Collaborate with health-care provider (HCP) regarding administration of IV fluids to support optimal hydration.
  • Monitor laboratory values that reflect alterations in fluid status: K+, BUN, Ca, Cr, Hgb, and Hct.
  • Administer replacement electrolytes, as ordered, to manage underlying cause of fluid alteration.
  • Monitor urine characteristics (color, dark) and respiratory status.
  • Monitor and trend vital signs.
  • Perform a daily weight with strict intake and output.

Fluid Volume, Excess

  • Facilitate management of fluid volume excess.
  • Monitor for abdominal ascites, measuring and trending abdominal girth.
  • Monitor and trend laboratory values: Alb, TP, and globulin.
  • Assess for dehydration and increase fluids if present; fluid shifts from intravascular to extravascular can result in concerns related to hydration status.
  • Administer ordered diuretics and monitor urinary output in response to therapeutic intervention.
  • Trend vital signs and daily weight, and perform strict intake and output.
  • Assess lungs for crackles, and evaluate for shortness of breath.
  • Assess neck for jugular venous distention.
  • Assess for dependent edema in hands and feet.

Gas Exchange, Risk

  • Administer oxygen as ordered; monitor and trend pulse oximetry.
  • Position in high Fowlers to maximize lung expansion.
  • Obtain baseline abdominal girth, measure and mark each shift or as needed to monitor growth.
  • Consider use of incentive spirometry.
  • Encourage deep breathing and repositioning.


  • Perform nasogastric intubation to remove gastric secretions and decrease pancreatic secretions, which may result in autodigestion.
  • Monitor nasogastric tube for patency and amount of drainage.
  • Assess bowel sounds frequently.
  • Measure and trend abdominal girth to monitor degree of abdominal distention.


  • Facilitate management of insufficient nutrition.
  • Measure weight daily.
  • Evaluate for muscle wasting.
  • Strictly monitor intake and output.
  • Consider a careful nutritional history that includes cultural food preferences.
  • Discuss frequent small meals with a diet high in calories from carbohydrates.
  • Consider recommending diet and vitamin supplements an possible parenteral nutrition.
  • Consider prescribed medications that may assist are antiemetics, and acid suppression agents.


  • Refrain from activities that may increase pain.
  • Apply heat or cold to the best effect in managing pain, and monitor pain severity.
  • Collaborate with the patient in selecting the best pain management modality with consideration of cultural implications.

Skin, Risk

  • Assess skin general condition noting any scratches, bruises, excoriation, rash.
  • Monitor bilirubin level as a level greater than 3 mg/dL facilitates jaundice and increases itching risk.
  • Discuss ways to protect the skin such as use of tepid water, alkaline soap, and emollient lotions.
  • Suggest keeping short fingernails and the use of mittens to discourage scratching.
  • Encourage use of loose-fitting cotton clothing, cool room temperatures, and administration of antihistamines can help decrease itching.

Nutritional Considerations

  • Encourage a well-balanced diet that includes foods high in fiber.
  • Consider that dietary recommendations will vary depending on disease condition and severity (e.g., a soft food diet is recommended if esophageal varices develop, fat substitutes are recommended if bile duct disease is diagnosed, and salt intake should be limited if ascites develop).
  • Discuss how a diet low in protein and other foods such as onions, gelatin, or string beans can decrease ammonia levels and may improve cognitive function.
  • Monitor and trend laboratory values that evaluate nutritional status (Alb, TP, K+), and collaborate with HCP on replacement strategies.
  • Administer ordered enteral or parenteral nutrition and evaluate the patient’s response.
  • Correlate laboratory values with IV fluid infusion, and collaborate with the HCP and pharmacist to adjust to patient needs.
  • Collaborate with the patient to ensure adequate pain control.
  • Monitor and trend vital signs for alterations associated with metabolic imbalances.

Clinical Judgement

  • Consider why personal choices have resulted in poor health outcomes, and which interventions are most likely to result in adaptation to a more healthy lifestyle and improved health.

Followup Evaluation and Desired Outcomes

  • Acknowledges contact information provided for the Centers for Disease Control and Prevention ( /diseasesconditions).
  • Understands information regarding causative factors of pancreatitis and liver disease, the disease process, and proactive lifestyle changes to better manage health.
  • Accepts the importance of adhering to the medication regimen as prescribed to limit pancreatic secretions and decrease pain.