What Is a Normal FibroScan Result and What Does It Mean?

A normal FibroScan liver stiffness result falls roughly between 3.9 and 5.3 kilopascals (kPa), based on a study of healthy organ donors that found an average reading of about 4.6 kPa. But that single number only tells part of the story, because what counts as “concerning” depends on your underlying condition, your body size, and even whether you ate before the exam. FibroScan also measures liver fat using a separate metric called the controlled attenuation parameter (CAP), which has its own set of reference values. Understanding both numbers, and the situations that can push them artificially higher, is what turns a printout into useful information.

What FibroScan Actually Measures

FibroScan uses a combination of ultrasound and a low-frequency vibration pulse to measure how stiff your liver tissue is. A small probe placed against your skin sends a gentle mechanical wave into the liver, and the device tracks how fast that wave travels through the tissue. Stiffer tissue transmits the wave faster, so higher speed translates to a higher stiffness number in kilopascals.¹ The underlying logic is straightforward: when the liver develops scar tissue (fibrosis), it becomes physically stiffer, and that stiffness shows up as a higher kPa reading.

Newer FibroScan models also calculate a CAP score during the same exam. CAP estimates how much fat has accumulated in the liver, reported in decibels per meter (dB/m). Where the stiffness measurement tells your doctor about scarring, the CAP score tells them about fatty change. Both numbers come from a single session and together they give a snapshot of two of the most common forms of liver damage.²

Normal Liver Stiffness in Healthy Adults

The best data on truly normal stiffness comes from people with no liver disease at all. A prospective study of healthy living organ donors in South Korea measured an average stiffness of 4.6 kPa, with values ranging from 3.3 to 5.6 kPa across the group. Using standard statistical cutoffs, the researchers defined the normal range as 3.9 to 5.3 kPa. Stiffness did not differ between men and women, and age had no measurable effect in that adult population.³ A separate study of healthy controls used for comparison with heart failure patients found a similar median of 4.4 kPa.⁴

If your result lands somewhere in the low-to-mid single digits, that is generally reassuring. Most clinicians consider anything below about 6 or 7 kPa to be in a range consistent with little or no fibrosis, though the exact threshold your doctor uses depends on why the scan was ordered.

How Cutoffs Shift Depending on the Liver Condition

One of the trickiest things about interpreting FibroScan results is that the thresholds for “mild,” “moderate,” and “severe” fibrosis are not universal. They change depending on the underlying cause of liver disease, because different diseases produce different patterns of scarring and inflammation. A reading of 9 kPa means something different in a person with alcohol-related liver disease than it does in someone with chronic hepatitis C.

In patients with chronic viral hepatitis (hepatitis B or C), a cutoff of about 6 kPa has been used to detect any fibrosis at all, while readings around 12 kPa signal possible cirrhosis.⁵ A large U.S. multicenter study of hepatitis B and C patients found that a stiffness cutoff of about 8.4 kPa identified moderate fibrosis or worse, while 12.8 kPa identified cirrhosis with good accuracy.⁶

For alcohol-related liver disease, a meta-analysis of over a thousand patients arrived at somewhat different numbers: roughly 7 kPa for any fibrosis, 9 kPa for significant fibrosis, about 12 kPa for severe fibrosis, and around 19 kPa for cirrhosis.⁷ These thresholds tend to run slightly higher than the viral hepatitis cutoffs, partly because alcohol-related disease is often accompanied by inflammation and swelling that independently raise stiffness readings.

In fatty liver disease (now called metabolic dysfunction-associated steatotic liver disease, or MASLD), a commonly used threshold for advanced fibrosis is a stiffness above 12 kPa.⁸ Meanwhile, a prospective study using a cirrhosis-specific cutoff of about 17.6 kPa achieved strong diagnostic accuracy across mixed liver disease populations.⁹

The takeaway: your specific result has to be interpreted against the disease your doctor suspects. A reading of 10 kPa might prompt concern in one clinical context but not another.

What the CAP Score Tells You About Liver Fat

The CAP number on your FibroScan report reflects how much fat has built up in your liver cells. The widely used cutoff for adults is around 248 dB/m; readings above this level suggest at least mild fatty liver. For children, a lower threshold of 225 dB/m is typically applied.¹⁰ A large study of over 5,300 examinations confirmed that CAP has reasonable accuracy for grading how much fat is present, performing best at distinguishing moderate-to-severe fatty change from milder levels.¹¹ Some research uses a threshold of 290 dB/m to flag advanced fat accumulation.⁸

There is a wrinkle, though. Research on healthy, non-obese people found that about one in five had CAP values above the commonly suggested cutoffs, which raises questions about whether the current thresholds are set too low. The same study calculated that a more accurate upper limit for healthy adults could be as high as 295 dB/m rather than 248.¹⁰ This is still being debated, so if your CAP score falls in the gray zone between roughly 240 and 300, your doctor may want additional context before calling it abnormal.

Things That Can Push Your Reading Higher Than It Should Be

FibroScan is measuring liver stiffness as a proxy for fibrosis, but several non-fibrosis factors can make the liver temporarily stiffer. If you are unaware of these, an elevated result can be alarming for the wrong reasons.

Eating Before the Exam

Food increases blood flow to the liver, which temporarily raises stiffness. One study found that stiffness climbed significantly within 30 minutes of a meal in patients with chronic liver disease, though the change was not statistically significant in healthy volunteers.¹² A more detailed study in hepatitis C patients showed that stiffness peaked 15 to 45 minutes after eating and did not return to baseline until about two hours later, with the spike growing more dramatic at higher fibrosis stages.¹³ Most centers ask you to fast for at least two hours before the test precisely for this reason.

Liver Inflammation and ALT Flares

Active inflammation in the liver can produce readings that look like advanced fibrosis even when actual scarring is mild or absent. In hepatitis B patients, those with significant inflammation had substantially higher rates of mis-staging: over half were placed in the wrong fibrosis category, compared with about a fifth of those with lower inflammation.¹⁴ Severe acute hepatitis or a major spike in liver enzymes (an ALT flare) is an even bigger confounder. Stiffness values during a flare can land squarely in the cirrhosis range despite no underlying scar tissue. Guidelines recommend waiting at least three months after ALT levels come down before trusting a FibroScan result, or at minimum until ALT drops below five times the upper limit of normal.¹⁵

Heart Failure and Liver Congestion

When the heart cannot pump blood efficiently, pressure builds up in the veins that drain the liver, causing the organ to swell and stiffen. Research has shown a direct, linear relationship between venous pressure in the liver and FibroScan readings.¹⁶ In a study comparing patients with different types of heart failure to healthy controls, people with right-sided heart failure had a median stiffness around 9.7 kPa, and those with acute decompensated heart failure reached about 11.2 kPa, both well above the healthy median of 4.4 kPa. Interestingly, aggressively removing fluid through diuretics did not immediately bring the stiffness down to normal levels.⁴ If you have heart failure, your doctor needs to factor congestion into the reading rather than automatically assuming the number reflects liver scarring.

Why the Probe Size Matters

FibroScan comes with two main probes: the standard M probe and the larger XL probe designed for people with a higher body mass. Which probe is used can meaningfully affect your result. A head-to-head comparison found that the XL probe consistently produced stiffness values about 20 percent lower than the M probe in the same patients, even though both probes correlated well with biopsy findings.¹⁷ The XL probe also dramatically improved success rates in overweight patients: one study found reliable results in 73 percent of patients with the XL probe compared to just 50 percent with the M probe, and failure rates dropped from 16 percent to about 1 percent.¹⁸

The practical implication is that cutoff values developed using the M probe may not directly apply when the XL probe is used, because the XL readings tend to run lower. Your report should specify which probe was used, and your doctor should interpret the number accordingly. If you are comparing two scans done at different times, check that the same probe was used both times, otherwise the comparison may be misleading.

What Makes a Scan Technically Reliable

Not every FibroScan exam produces a trustworthy number. The device’s manufacturer originally set three quality criteria: at least 10 valid measurements during the session, a success rate of 60 percent or higher (meaning at least 6 out of 10 attempts produce a valid reading), and an interquartile range-to-median ratio (IQR/M) no greater than 30 percent.¹⁹ The IQR/M is essentially a measure of how consistent the individual readings are. If the ratio exceeds 30 percent, the individual measurements were bouncing around too much and the median may not be trustworthy.

If your report notes that the exam did not meet these quality thresholds, your doctor will likely want to repeat it or pursue an alternative assessment. Technical failure is more common in people with a larger body habitus, narrow rib spaces, or significant amounts of fluid in the abdomen (ascites). In those situations, switching to the XL probe or using an alternative imaging method may be the next step.

Liver Stiffness in Children and Adolescents

If your child had a FibroScan, the adult reference ranges do not apply directly. Children’s livers become progressively stiffer as they grow. A study of healthy children using transient elastography found median stiffness of about 3.4 kPa in preschoolers, 3.8 kPa in elementary-age children, and 4.1 kPa in adolescents.²⁰ Other studies using different elastography methods confirm that stiffness rises steadily until the early-to-mid teen years before leveling off.²¹²²

This means a stiffness reading of 5.5 kPa might be well within normal limits for a 40-year-old but worth a closer look in a 6-year-old. Pediatric gastroenterologists use age-appropriate reference charts, and the interpretation of an abnormal result should factor in the child’s specific age group.

What Happens After an Elevated Result

A high FibroScan number does not automatically mean you need a liver biopsy. Many clinicians now combine the FibroScan result with simple blood-based scoring systems to improve accuracy before deciding on next steps. One study in fatty liver disease patients found that pairing a stiffness measurement with a blood-based fibrosis score caught advanced fibrosis with about 89 percent sensitivity and ruled it out with about 93 percent confidence, a significant improvement over either test alone.²³ A separate analysis showed that using tests in sequence, running the second test only in patients whose first result was ambiguous, reduced wrong classifications while keeping the rate of uncertain results manageable.²⁴

This stepwise approach has also reshaped how healthcare systems handle fatty liver disease referrals. Introducing non-invasive testing pathways in community settings has more than doubled the detection of advanced fibrosis while cutting unnecessary specialist referrals by as much as 85 percent, saving substantial costs in the process.²⁵ Additional modeling work confirms that adding a non-invasive test to the diagnostic pathway reduces the number of liver biopsies that turn out to have been unnecessary.²⁶

Tracking Changes Over Time

If your doctor orders repeat FibroScans months or years apart, the goal is usually to see whether fibrosis is progressing, stable, or improving with treatment. European guidelines have suggested repeating non-invasive tests every three years in patients with early-stage fatty liver disease and annually in those with more advanced disease.²⁷ Whether FibroScan is actually the best tool for tracking small changes over time remains an open question, however. Some research has found that blood-based scores do not reliably track slow progression year to year, and the degree to which FibroScan captures gradual shifts better than those scores is still being studied.

When comparing serial scans, keep the confounders in mind. If your first scan was done fasting and your second was done after lunch, or if one used the M probe and the other the XL, the numbers are not directly comparable. Consistency in testing conditions matters as much as the raw result. Ask your doctor whether the same conditions and probe were used each time, and whether any change in readings might reflect a real shift in liver health or just measurement noise.