Primary biliary cholangitis (PBC) is officially classified as a rare disease. The global prevalence is about 18 cases per 100,000 people, which means roughly 1 in 5,500 people has the condition. While that places PBC firmly in the “rare” category, it is not as uncommon as many other rare diseases, and the number of diagnosed cases has been climbing steadily for decades.
PBC by the Numbers
A 2025 meta-analysis covering 59 studies, 381 million participants, and over 129,000 PBC patients across 25 countries found a pooled global prevalence of 18.1 per 100,000 people. The annual incidence, meaning newly diagnosed cases each year, sits at about 1.8 per 100,000 person-years. To put that in perspective, for every million people in a population, roughly 18 new cases of PBC will be diagnosed each year.
Prevalence varies widely by region. Reported rates range from as low as about 2 per 100,000 in some areas to over 40 per 100,000 in others. Countries at higher latitudes and those with higher development indices tend to report more cases. The Americas show particularly high prevalence, while the Western Pacific region has seen the fastest growth in diagnosed cases over time.
Why It Overwhelmingly Affects Women
PBC has one of the most extreme gender skews of any disease. The female-to-male ratio reaches as high as 10 to 1, meaning for every man diagnosed, up to ten women receive the same diagnosis. This pattern is consistent with PBC’s classification as an autoimmune disease, since the immune system’s tendency to attack the body’s own tissues is far more common in women across many conditions.
Among women over 40, roughly 1 in 1,000 has PBC. That figure makes PBC relatively common within this specific demographic, even though it qualifies as rare in the general population. In many European and Asian countries, prevalence in women is five times higher than in men, and incidence is four times higher.
Typical Age at Diagnosis
Most people learn they have PBC between the ages of 40 and 60, though the disease peaks in prevalence among those aged 60 to 79. It is exceptionally rare in anyone under 25. Interestingly, the average age at diagnosis has been creeping upward since the 1970s, rising by about two to three years per decade. People diagnosed more recently also tend to have milder disease at the time of diagnosis, with less liver damage and better lab results than those caught in earlier eras. This likely reflects improved screening and earlier detection through routine blood work rather than a true change in the disease itself.
Is PBC Becoming More Common?
The number of people living with PBC has been rising globally. Several factors likely contribute to this trend. Better awareness among doctors means more cases are caught, particularly mild ones that might have gone undiagnosed decades ago. Blood tests that detect the signature antibodies associated with PBC are now routine in many settings when liver enzymes come back abnormal. Longer life expectancy also plays a role: since PBC is a chronic, slowly progressive disease most common in older adults, more people are living long enough to be diagnosed and to live with the condition for years.
Whether the actual biological occurrence of PBC is increasing, or whether we are simply getting better at finding it, remains an open question. Both factors probably contribute.
How PBC Compares to Other Rare Diseases
In the United States, a disease is classified as rare if it affects fewer than 200,000 people. The European Union uses a threshold of 5 per 10,000 (or 50 per 100,000). PBC falls well within both definitions. The European Medicines Agency explicitly recognizes PBC as a rare disease in its regulatory guidance for drug development.
That said, PBC sits at the more common end of the rare disease spectrum. Conditions like Huntington’s disease (about 5 per 100,000) or ALS (about 5 per 100,000) have similar prevalence. Truly ultra-rare diseases affect fewer than 1 per 100,000. So while PBC is uncommon enough that many general practitioners will see only a handful of cases in their careers, it is well-studied compared to diseases that affect only a few hundred people worldwide.
What “Rare” Means for Patients
Living with a rare disease often means delayed diagnosis, limited treatment options, and difficulty finding specialists. PBC shares some of these challenges. Many patients report years of unexplained fatigue and itching before a diagnosis is made, partly because the condition progresses slowly and partly because not all doctors think to test for it. The renaming of the disease in 2015, from “primary biliary cirrhosis” to “primary biliary cholangitis,” was itself an effort to reduce stigma and confusion, since many patients never develop cirrhosis at all.
On the treatment side, PBC patients are better off than those with many rare diseases. A well-established first-line medication has been available for decades, and people diagnosed today with milder disease tend to respond well to treatment. Newer therapies have also been approved for those who don’t respond adequately to initial treatment. The outlook for someone diagnosed with PBC in 2025 is considerably better than it was even 20 years ago.