If a clinic letter has just told you your Harvey-Bradshaw Index is 9, here is the quick translation: under 5 is reported as clinical remission, 5 to 7 as mild, 8 to 16 as moderate and above 16 as severe. So 9 sits at the low end of a moderate band that is twice as wide as all the other bands put together.
That is the part every calculator page will tell you. What almost none of them tell you is the more useful part: what the number is actually made of, how easily it moves for reasons that have nothing to do with your disease, and why a low score is not a certificate that your bowel has healed. This guide is written for the person holding the number, not for the clinician who generated it.
What the Harvey-Bradshaw Index score means
The total is a symptom score for a single day, banded into four categories. Clinical remission is a total under 5, mild disease is 5 to 7, moderate is 8 to 16, and severe is above 16.
| Total score | Label used in clinic | What it is describing |
|---|---|---|
| Under 5 | Clinical remission | Little or no symptom burden on the day scored |
| 5 to 7 | Mild | Some symptoms, usually a small number of loose stools or mild pain |
| 8 to 16 | Moderate | A wide range, from noticeable daily disruption to near-constant symptoms |
| Above 16 | Severe | Heavy symptom burden, often with complications counted in |
Two things about that table are worth pausing on. The first is that the remission threshold has an evidence base: when almost 1,000 paired assessments from the PRECiSE certolizumab trials were compared, a Harvey-Bradshaw total of 4 or less corresponded to the Crohn's Disease Activity Index remission cut-off of 150 or less (Vermeire 2010). The second is that the word "remission" here means clinical remission only. It is a statement about how you felt yesterday, not about what a camera or a stool test would find.
That gap is the single most misread thing about this score, and the rest of this guide is largely about it.
The five items, and what each one is really asking
The index has five components, added with no weighting at all. It was published in 1980 by Richard Harvey and John Bradshaw as a deliberately crude, one-day simplification of the much longer Crohn's Disease Activity Index, which needed a seven-day diary and blood tests (Harvey 1980).
| Item | Scoring | The catch |
|---|---|---|
| General well-being yesterday | 0 very well, 1 slightly below par, 2 poor, 3 very poor, 4 terrible | Entirely subjective, and sensitive to sleep, mood, work stress and everything else in your life |
| Abdominal pain yesterday | 0 none, 1 mild, 2 moderate, 3 severe | Also subjective, and pain from a stricture or adhesions scores exactly the same as pain from inflammation |
| Number of liquid or soft stools yesterday | 1 point per stool, no upper limit | The only unbounded item, so it can dominate the total on its own |
| Abdominal mass | 0 none, 1 dubious, 2 definite, 3 definite and tender | Requires a clinician's hands on your abdomen, so you cannot score it at home |
| Complications | 1 point each for eight listed items, including joint pain, eye inflammation, skin lesions, mouth ulcers, anal fissure, new fistula and abscess | Joint pain scores the same single point as an abscess |
Look at the last column. Every one of those catches is a reason two identical totals can mean completely different things. The instrument was never designed to be precise; it was designed to be fast enough that a busy clinician would actually use it, and consistent enough to compare a patient against themselves over time. Activity indices of this kind exist mainly as efficacy endpoints for clinical trials, which is the context the whole family of scores was reviewed in by the International Organization for the Study of IBD's trials task force (Sandborn 2002).
Why the stool count can swallow the whole score
The stool item has no ceiling, and each liquid or soft stool adds one point. That single design choice explains most of the odd scores people find confusing.
Work it through. Someone with six liquid stools a day, mild pain and a general feeling of being slightly below par scores 6 plus 1 plus 1, which is 8: moderate disease. Someone with two liquid stools, severe pain and who felt terrible all day scores 2 plus 3 plus 4, which is 9: also moderate, and marginally worse on paper. Those are not similar experiences, but the index cannot tell them apart.
It also means the score moves for reasons outside your Crohn's. Two extra loose stools from a stomach bug, a course of antibiotics, a very high fibre day or a laxative effect all add two points. A bad night's sleep can move the well-being item by one or two. Over a few readings this noise averages out, which is exactly why a trend is worth more than any single number.
There is a related trap with the definition of "liquid or soft". The index does not use the Bristol Stool Scale, so what counts as soft is left to interpretation. If you are scoring yourself over time, pick one interpretation and stick to it, otherwise your own trend line becomes uninterpretable. Our guide on keeping a useful food and symptom diary covers the same principle: a consistent definition beats a precise one.
Why "moderate" covers everything from 8 to 16
The bands are not evenly spaced, and the moderate band is enormous. Remission spans five values, mild spans three, and moderate spans nine. That is not a flaw anyone hid; it follows from the score being unbounded at the top of the stool item.
The practical consequence is that "moderate" is close to uninformative on its own. A person scoring 8 and a person scoring 16 both get the same word in the letter. In one r/CrohnsDisease thread, someone newly diagnosed reported being told a score of 9 meant their Crohn's was "moderate-severe", and used that to ask how likely they were to need surgery (r/CrohnsDisease thread). Nine is in the moderate band, near its floor. The distance between that and the severe threshold is another seven points.
What your score cannot tell you: whether you are inflamed
This is the limitation that matters most, and it is well documented. A low Harvey-Bradshaw score is not evidence that your bowel has healed.
The clearest test of this came from a prospective cohort of 88 people with Crohn's who were having a colonoscopy, scored before the endoscopist saw anything. Clinical remission defined by the index predicted endoscopic remission with an area under the curve of 0.54, barely distinguishable from guessing. In people who had already had an ileocolonic resection it was 0.52. Adding a patient's own impression of their disease state, the clinician's impression and a CRP result lifted the figure to 0.88 in people without previous surgery (Zittan 2017). The symptom score alone was the weakest ingredient.
A secondary care cohort of 356 people with IBD found the same pattern from a different angle. Clinical disease activity was associated with mucosal inflammation in ulcerative colitis but not in Crohn's, and the authors concluded plainly that patient-reported symptoms and the Harvey-Bradshaw Index were poor predictors of mucosal inflammation in Crohn's (Gracie 2016).
And it is not just this one index. A 2025 systematic review of patient-reported outcome measures across IBD found only weak positive correlations with endoscopic scores in Crohn's, and limited concordance with faecal calprotectin and CRP. Its conclusion was that these measures offer valuable complementary insight from the patient's perspective but cannot replace objective measures of activity (Calvet 2025).
The same disconnect shows up in the big trials. In an analysis of the SONIC trial, only 53% of people who reached clinical remission by the CDAI at week 26 had actually healed their mucosa, and the authors wrote that clinical symptoms as scored by the index are not a reliable measure of the underlying inflammation (Peyrin-Biroulet 2014).
The other direction: a high score with a quiet gut
The arrow points both ways, and this is the version people find more distressing. You can score 10 or 12 while your colonoscopy, your calprotectin and your CRP all look reassuring.
A question that comes up constantly in r/CrohnsDisease is some version of "my colonoscopy was normal and my doctor says I am in remission, so why do I still feel awful?" (r/CrohnsDisease thread). The most upvoted replies in that thread listed exactly the right suspects: IBS-type symptoms, perianal problems, pain from strictures or surgical adhesions, and reflux. They are not medical evidence, but they match what the literature finds.
IBS-type symptoms. A meta-analysis of 27 studies and 3,169 people with IBD in remission found IBS-type symptoms were common across the board (Fairbrass 2020). In one prospective study, nearly 60% of people with Crohn's in physician-assessed remission met Rome II criteria for IBS. Importantly, calprotectin in that group was higher than in those without such symptoms, which suggested that low-grade inflammation, rather than a second separate condition, explained a lot of it (Keohane 2010). Feeling IBS-like is a reason to test, not a reason to conclude.
Bile acid malabsorption after surgery. If part of your terminal ileum has been removed, bile acids that would normally be reabsorbed there reach the colon and cause watery diarrhoea. In a series of 91 people with Crohn's who had a previous resection and were tested, the length of ileum removed correlated with the severity of bile acid malabsorption (Skouras 2019). That diarrhoea adds a point per stool to your score without any active inflammation behind it.
Small intestinal bacterial overgrowth. A meta-analysis of 11 studies found SIBO in about 22% of people with IBD, with odds roughly ten times higher than in non-IBD controls in Crohn's specifically. The odds were higher again with fibrostenosing disease and with previous bowel surgery, especially removal of the ileocaecal valve (Shah 2019). Bloating, wind and loose stools from overgrowth score identically to bloating, wind and loose stools from inflammation.
Mood, and the well-being item. A meta-analysis found roughly a third of people with IBD had symptoms of anxiety and about a quarter had symptoms of depression, rising to over half and around a third respectively during active disease (Barberio 2021). The Gracie cohort also found that somatisation was associated with clinical disease activity scores in both Crohn's and colitis, independently of inflammation (Gracie 2016). None of that means the symptoms are imagined. It means a four-point item called "general well-being" is going to capture more than your bowel does.
For the fuller version of this problem, including flare look-alikes such as C. difficile and stricturing disease, our guide on telling whether you are actually in a Crohn's flare covers the tests that settle it. And if you suspect stress is driving your numbers up, what the prospective research shows about stress and Crohn's flares goes through the evidence rather than the folklore.
Clairop logs meals, symptoms and stool in seconds, then looks for the foods your gut reacts to, including reactions that land days later.
Scoring it yourself is not quite the same measurement
Two of the five items are pure self-report, one is a count only you can do, and one, abdominal mass, needs a physical examination. So a home score is a four-item version of a five-item index, and it behaves differently.
The cleanest evidence comes from a Dutch study that built a patient version and compared it against the clinician's assessment on the same day in 181 people. The two correlated strongly overall, but patients scored themselves systematically higher: a median patient score of 4 against a clinician median of 2. Agreement on the binary question of active disease versus remission was 77%, with a kappa of 0.52, which is moderate rather than good. The authors noted that patients tended to report more symptoms on the questionnaire than they reported to the clinician in the room (Bennebroek Evertsz' 2013).
That last observation cuts both ways. It may mean patients over-report on paper. It may equally mean people under-report in a short consultation. Either way, if your own number comes out higher than the one in your clinic letter, the difference is expected and not a sign anyone made a mistake.
A larger Spanish study, MediCrohn, took a more optimistic reading. Across 385 paired assessments, a mobile app version self-completed by the patient agreed with in-clinic physician scoring on remission versus activity 92.4% of the time, with a kappa of 0.80. The positive predictive value for remission was 98.2%, but the negative predictive value was 76.7% (Echarri 2020). In plain terms: when a self-scored app said "remission", it was almost always right in the clinician's terms too; when it said "active", it was considerably less reliable.
What a change in your score actually means
Change is the thing this index is genuinely good at, and it is where the number earns its keep.
The conventional threshold is a fall of 3 points, which came from mapping the two indices onto each other: a 3-point move on the Harvey-Bradshaw scale corresponded to the 100-point CDAI change used to define clinical response in trials (Vermeire 2010). If your score has gone from 11 to 7 since starting a new treatment, that is a response by the usual definition.
How well the two scores map onto each other is worth knowing honestly. The original 1980 paper reported a correlation of 0.93 with the CDAI, a figure still quoted. Vermeire's much larger analysis of almost 1,000 data pairs found a Spearman correlation of 0.800, which is strong but noticeably lower (Vermeire 2010). William Best, one of the original architects of the CDAI, went further: he pointed out that correlation is an incomplete way to assess sameness, plotted 224 patients, and found each one-point rise corresponded on average to a 27-point rise in CDAI, with 95% prediction limits wide enough that he described the relationship as "good but far from perfect" (Best 2006).
There is a newer conversion too. Many modern registration trials use a two-item patient-reported outcome, PRO-2, built from abdominal pain and stool frequency. An analysis of a phase 3 vedolizumab trial found PRO-2 and the Harvey-Bradshaw total correlated strongly, with an approximate conversion of one Harvey-Bradshaw point for every two PRO-2 points, though the prediction intervals were wide (Khanna 2025). That is useful if you are trying to read a trial result and translate it into the score your clinic uses.
A worked example: two people, both scoring 9
| Item | Person A | Person B |
|---|---|---|
| General well-being | 1 (slightly below par) | 3 (very poor) |
| Abdominal pain | 1 (mild) | 3 (severe) |
| Liquid or soft stools yesterday | 6 | 2 |
| Abdominal mass | 0 | 0 |
| Complications | 1 (joint pain) | 1 (mouth ulcers) |
| Total | 9 | 9 |
Both letters will say "moderate". Person A's score is almost entirely a frequency problem: six stools, minimal pain, coping reasonably. If they have had an ileal resection, bile acid malabsorption is worth ruling in or out before anyone assumes the Crohn's is active (Skouras 2019). Person B's score is almost entirely a distress and pain problem with near-normal bowel frequency, which raises different questions: a stricture, overlapping gut-brain symptoms, or inflammation that the stool count is not reflecting.
The total is the same. The conversation should not be. This is why the item breakdown belongs in your notes, and why a single figure copied into a letter loses most of the information that generated it.
Where the score fits in modern Crohn's monitoring
Symptom scores are still useful, but treatment targets have moved beyond them, and knowing that stops you over-reading your number in either direction.
The STRIDE-II consensus from the International Organization for the Study of IBD set symptomatic relief and normalisation of blood and stool markers as short-term targets, with clinical remission and endoscopic healing as the long-term targets, alongside absence of disability and restored quality of life (Turner 2021). Your symptom score is on that list. It is the first step, not the destination.
The CALM trial showed why that distinction has teeth. It randomised 244 people with active Crohn's to treatment escalation driven by symptoms alone, or by symptoms combined with calprotectin and CRP. At 48 weeks, 46% of the biomarker-guided group had reached mucosal healing without deep ulcers, against 30% of the symptom-guided group (Colombel 2017). Treating what you can feel, and only what you can feel, produced measurably worse healing.
Which objective tests carry the weight? Faecal calprotectin correlates more closely with the Simple Endoscopic Score for Crohn's disease than CRP, blood leukocytes or the CDAI do (Schoepfer 2010). CRP is cheaper and faster but plainly imperfect: a Mayo Clinic series examined how it lined up with clinical, endoscopic, histological and radiographic activity and found the relationship far from reliable (Solem 2005). Both ACG and ECCO guidance frame Crohn's management around combining these objective measures with the clinical picture rather than choosing between them (Lichtenstein 2018; Torres 2020).
One setting where the symptom score does surprisingly well is after surgery. In 86 people who had had an ileocolonic resection and then a colonoscopy, the area under the curve for predicting endoscopic recurrence was 0.698 for calprotectin and 0.710 for both CRP and the Harvey-Bradshaw Index. Combining CRP with the symptom score gave a positive predictive value of 95.7% (Verdejo 2018). The lesson is not that the score is better than people think; it is that combinations beat any single measure.
How to use your own score without over-reading it
If you want your number to be worth something, a few habits make the difference.
Score the same way every time. Pick your definition of a liquid or soft stool and keep it. Score for the same period, which is the previous day, not "lately". Inconsistent scoring produces a trend line that looks like disease change and is not.
Record the items, not just the total. A total of 9 is nearly meaningless three months later. "Well-being 1, pain 1, stools 6, mass 0, complications 1" still says something useful.
Take several readings, not one. A single day is a small sample of a fluctuating condition. Three or four scores across a fortnight tell you far more than the one you happened to record the morning of your appointment.
Note the confounders beside the score. Antibiotics, a new medication, a stomach bug, a very short night, a period, a week of deadlines. These move the number without moving your disease.
Agree in advance what change would prompt a call. A number that never leads to an action is just admin. "If my score is above 8 for a week, or it has risen by 3 or more from where it usually sits, I contact the IBD nurse" is a plan. It is worth setting that threshold with your own team rather than borrowing one from the internet, because a stable baseline of 6 means something different from a stable baseline of 1.
Take it to the appointment in a form someone can read in a minute. Clinic slots are short. A single page with your scores, their dates, the item breakdown for the worst few days and any test results beats a fortnight of raw diary entries. Our guide to what a doctor actually reads on a symptom tracker handover covers what belongs on that page. Our piece on what to ask your gastroenterologist about Crohn's covers the conversation itself, and what a Crohn's-specific tracking app needs to capture covers getting the data in without it becoming a second job.
If you would rather not do the arithmetic yourself, Clairop builds the Harvey-Bradshaw Index for Crohn's from answers you have already given while logging, shows the score broken into its published items rather than as a bare total, and puts it on a one-page report for your appointment with the source of each number stated above it. It does not interpret your disease and it is not a substitute for your IBD team's assessment.
If you want a measure that captures the things this index leaves out, ask your team about IBD-Control, a short generic questionnaire developed and validated specifically to measure disease control from the patient's point of view, including the parts of living with IBD that a stool count misses (Bodger 2014).
Myths about the Harvey-Bradshaw Index
"A score under 5 means my Crohn's is healed." It means your symptoms were quiet on the day scored. Around half of people in clinical remission in the SONIC analysis still had endoscopic or CRP evidence of active disease (Peyrin-Biroulet 2014).
"A high score means I am flaring." Not necessarily. Bile acid malabsorption, bacterial overgrowth, strictures, gut-brain symptoms and a rough patch of mood can all raise it without inflammation behind it (Skouras 2019; Shah 2019; Gracie 2016).
"It is basically the same as the CDAI." It correlates well but not interchangeably. One point corresponds to about 27 CDAI points on average, with prediction limits wide enough that the original analyst called the relationship far from perfect (Best 2006).
"My score went up two points, so my disease is worse." Two extra loose stools do that on their own. Three points is the usual threshold for a meaningful change, and it is more trustworthy across several readings than between two (Vermeire 2010).
"Higher score means more inflammation, proportionally." There is no such proportionality. The index is not weighted, and an abscess scores the same single point as joint pain (Harvey 1980).
"If my calprotectin is normal, my symptoms are not real." They are real. The Keohane study is a good corrective in both directions: symptoms in apparent remission often did come with raised calprotectin, and where they did not, the symptoms still needed explaining and managing (Keohane 2010).
When to contact your IBD team, and when not to wait
A rising score is a prompt to get in touch, not to self-manage. Contact your IBD team promptly if your score has climbed by 3 or more points from your usual level and stayed there for a week or more, if a new complication has appeared on the list, or if you are being kept awake at night by symptoms.
Some things should not wait for a score at all. See a doctor promptly if you have blood in your stool, a fever, unexplained weight loss, severe or worsening abdominal pain, vomiting with an inability to pass stool or wind, a new or increasing swelling or lump in your abdomen, a new opening or discharge near the anus, or signs of anaemia such as breathlessness and marked fatigue. Severe pain with vomiting and no bowel movement can indicate an obstruction and needs urgent assessment, not a note in a diary.
Nothing in this guide is a reason to start, stop or change any medication, and a good score is not a reason to skip a scheduled test. Any change to treatment is a conversation with the team who know your disease history and your imaging.
The honest bottom line
The Harvey-Bradshaw Index is a good instrument doing a narrow job. It turns a fluctuating illness into a number that can be compared against the same number from last quarter, and it takes about a minute. That is genuinely valuable, especially for remote monitoring, and the evidence supports using it that way (Echarri 2020; de Jong 2017).
What it is not is a window into your bowel. The people who built these indices knew that, the guidelines now say it explicitly, and the trial evidence shows that managing Crohn's on symptoms alone produces less healing than managing it on symptoms plus objective markers (Colombel 2017; Turner 2021).
So read your score as one line in a longer report. Ask which items produced it. Track the direction, not the digit. And treat both a reassuring number and an alarming one as the start of a question rather than the end of one.
