The Child-Pugh score is a point-based system that rates the severity of liver cirrhosis on a scale from 5 to 15. Doctors use it to estimate how well (or poorly) the liver is still functioning, which helps guide treatment decisions, assess surgical risk, and predict survival. Each patient is placed into one of three classes: A (mild), B (moderate), or C (severe).
How the Score Is Calculated
The Child-Pugh score adds up points from five different measures of liver function. Each one is scored 1, 2, or 3 based on severity, so the lowest possible total is 5 (all normal) and the highest is 15 (all severely abnormal). Three of the five measures come from blood tests, while two are based on a doctor’s clinical assessment.
The five components are:
- Bilirubin: A waste product the liver clears from your blood. Levels below 2 mg/dL score 1 point, 2 to 3 scores 2 points, and above 3 scores 3 points. High bilirubin is what causes jaundice, the yellowing of skin and eyes.
- Albumin: A protein your liver produces. Levels above 3.5 g/dL score 1 point, 2.8 to 3.5 scores 2, and below 2.8 scores 3. Low albumin signals the liver is struggling to keep up with its basic manufacturing job.
- Prothrombin time (or INR): This measures how quickly your blood clots. The liver makes most clotting factors, so slower clotting means worse liver function. A prothrombin time less than 4 seconds above normal scores 1, 4 to 6 seconds scores 2, and more than 6 seconds scores 3.
- Ascites: Fluid buildup in the abdomen. None scores 1 point, easily controlled ascites scores 2, and poorly controlled ascites scores 3.
- Hepatic encephalopathy: Confusion or brain fog caused by toxins the liver can no longer filter. Absent encephalopathy scores 1, mild or minimal symptoms score 2, and advanced confusion or disorientation scores 3.
The two subjective components, ascites and encephalopathy, are sometimes criticized because different doctors can grade them differently. But the score remains one of the most widely used tools in liver disease because it’s quick and doesn’t require any specialized testing beyond routine bloodwork and a physical exam.
What Each Class Means
Once the five scores are totaled, the patient falls into one of three classes:
- Class A (5 to 6 points): Well-compensated cirrhosis. The liver is scarred but still handling most of its workload. One-year survival is approximately 100%, and two-year survival is around 85%.
- Class B (7 to 9 points): Significant functional compromise. The liver is falling behind, and symptoms like fluid retention or mild confusion may be present. One-year survival drops to about 80%, with two-year survival around 60%.
- Class C (10 to 15 points): Decompensated cirrhosis. The liver can no longer meet the body’s needs, and serious complications are common. One-year survival is roughly 45%, and two-year survival is about 35%.
These survival numbers are population averages, not individual predictions. But they give a clear picture of how dramatically outcomes shift as the score climbs. The gap between Class A and Class C is enormous.
Why It Matters for Surgery
One of the most practical uses of the Child-Pugh score is evaluating whether a patient with liver disease can safely undergo surgery. The liver plays a central role in blood clotting, drug metabolism, and immune function, all of which are critical during and after an operation.
Patients classified as Child-Pugh A generally tolerate surgery well, with early mortality rates around 6% in studies of elective procedures. For patients with Class B or C disease, the picture is starkly different. Two-year mortality following general surgery in these groups can approach 60% to 80%. In one study of elective joint replacement, 64% of patients with Class B or C cirrhosis died early compared to 6% of those with Class A. This is why many surgeons will delay or avoid elective procedures in patients with advanced cirrhosis unless the benefit clearly outweighs the risk.
How It Guides Medication Dosing
The liver processes most medications, breaking them down so the body can use and eventually eliminate them. When the liver is impaired, drugs can build up to dangerous levels at standard doses. The U.S. Food and Drug Administration uses the Child-Pugh classification as its standard framework for categorizing hepatic impairment in drug labeling, similar to how kidney function tests are used for renal dosing.
The FDA recommends that pharmaceutical companies test new drugs across all three Child-Pugh categories. In practice, if a drug’s clearance is significantly reduced in patients with moderate impairment (Class B), the label will typically recommend dose reductions for mild and moderate impairment and may contraindicate the drug entirely in severe impairment (Class C). This is why you’ll see phrases like “not recommended in severe hepatic impairment” on many medication labels. That language traces directly back to the Child-Pugh system.
Child-Pugh vs. MELD Score
The other major scoring system for liver disease is the Model for End-Stage Liver Disease, or MELD score. While Child-Pugh uses five variables (two of them subjective), MELD relies on just three lab values: bilirubin, creatinine (a kidney function marker), and INR. Every component of MELD is objective, which eliminates the variability that comes with grading ascites and encephalopathy.
MELD was originally developed to predict outcomes after a specific liver procedure, but it’s now the standard tool for prioritizing patients on the liver transplant waiting list. Because it produces a continuous numerical score rather than broad categories, it’s better at distinguishing between patients who have similar levels of illness. Two patients who both fall into Child-Pugh Class B might have meaningfully different MELD scores.
In everyday clinical practice, the two scores serve slightly different roles. Child-Pugh is more commonly used for general prognostic discussions, surgical risk assessment, and medication dosing. MELD is the go-to for transplant allocation and situations requiring finer discrimination between patients. Many hepatologists use both.
Limitations Worth Knowing
The Child-Pugh score has real limitations. The two subjective components, ascites and encephalopathy, can vary depending on who’s doing the assessment. Mild ascites detectable only on ultrasound might be graded as “none” by one clinician and “present” by another. Similarly, subtle encephalopathy can be easy to miss or overdiagnose.
The score also treats each of its five components as equally important, assigning equal weight to all of them. In reality, some factors may carry more prognostic significance than others depending on the clinical situation. And because the score tops out at 15, it doesn’t capture differences among the sickest patients very well. Someone scoring 11 and someone scoring 15 are both Class C, but their conditions can look very different.
Despite these drawbacks, the Child-Pugh score has remained in widespread use for decades because it’s simple, fast, and correlates meaningfully with real outcomes. For a bedside tool that requires only basic blood tests and a physical exam, it does a remarkable job of sorting patients into groups with genuinely different prognoses.