Primary sclerosing cholangitis (PSC) is a chronic liver disease in which the bile ducts inside and outside the liver become inflamed, scarred, and progressively narrowed. Over time, this scarring blocks the flow of bile, a fluid your liver produces to help digest fats. The buildup damages liver tissue and can eventually lead to liver failure. PSC is typically diagnosed around age 40 and affects men twice as often as women.
How PSC Develops
Your bile ducts form a branching network of tubes that carry bile from the liver to the small intestine. In PSC, the immune system triggers inflammation along these ducts, and repeated cycles of inflammation lay down scar tissue. The ducts stiffen, narrow, and sometimes close off entirely. Bile that can’t drain properly backs up into the liver, causing further injury to liver cells.
This process happens slowly, often over a decade or more. Transplant-free survival from the time of diagnosis ranges from a median of 9 to 21 years, depending on how advanced the disease is when it’s caught. Because the scarring is gradual, many people have no symptoms at all when they’re first diagnosed. PSC is frequently discovered by accident, when blood tests done for another reason reveal abnormal liver enzymes.
Symptoms to Recognize
When symptoms do appear, the most common ones are itchy skin, fatigue, and abdominal pain. As the disease progresses, you may notice jaundice (a yellowish tint to the skin and whites of the eyes), diarrhea, or episodes of fever and chills. Fever typically signals a bacterial infection in the blocked bile ducts, a complication called bacterial cholangitis that can require hospitalization.
The itching in PSC can be severe and unrelenting, sometimes becoming the single most disruptive symptom. It’s caused by bile salts accumulating in the bloodstream and depositing in the skin rather than draining normally into the intestine.
The Strong Link to Inflammatory Bowel Disease
One of the most striking features of PSC is its overlap with inflammatory bowel disease (IBD). Nine out of 10 people with PSC also have some form of IBD, most commonly ulcerative colitis. The connection runs in one direction more than the other: while most PSC patients have IBD, only a small fraction of IBD patients develop PSC.
Researchers still don’t fully understand why these two diseases travel together. The leading theory involves immune cells that are initially activated in the gut, then migrate to the liver and attack the bile ducts. Because of this overlap, anyone diagnosed with PSC is typically screened for IBD with a colonoscopy, even if they have no bowel symptoms.
What Causes PSC
PSC is considered an autoimmune condition, but its exact trigger remains unknown. Genetics play a clear role. Several immune-system genes in the HLA family are strongly linked to PSC risk, with a variant called HLA-B*08 representing the strongest known genetic risk factor. Other gene combinations either raise or lower susceptibility. Having a first-degree relative with PSC increases your own risk.
That said, genetics alone don’t explain the disease. Environmental factors, gut bacteria, and the interaction between the intestinal immune system and the liver all appear to contribute. PSC is not caused by alcohol use, viral hepatitis, or anything a person did or didn’t do.
Cancer Risk in PSC
PSC raises the risk of several cancers, and bile duct cancer (cholangiocarcinoma) is the most concerning. The estimated lifetime prevalence of cholangiocarcinoma in PSC patients ranges from 6 to 13 percent. This cancer can develop at any point in the disease, not just in the late stages, which is why ongoing surveillance matters.
Gallbladder cancer and colorectal cancer (especially in patients who also have IBD) are also more common. The American Gastroenterological Association recommends that people with PSC undergo imaging of the bile ducts and gallbladder, with or without a blood marker called CA 19-9, every 6 to 12 months. Patients with concurrent IBD need regular colonoscopies as well, typically on an annual basis, because the combination of PSC and ulcerative colitis raises colorectal cancer risk above what either condition would cause alone.
Treatment Options
There is currently no medication proven to slow or reverse the scarring in PSC. A bile acid supplement called ursodeoxycholic acid (often shortened to “urso”) was studied extensively because it improves liver blood tests in PSC patients. However, a major trial found that high-dose urso did not improve survival and was actually linked to more serious complications. Patients on the high dose were 2.3 times more likely to reach a serious disease endpoint than those on placebo. As a result, major liver disease guidelines recommend against using high-dose urso for PSC.
Treatment instead focuses on managing symptoms and complications. Itching can be treated with specific medications that reduce bile salt levels in the blood. Bacterial cholangitis episodes are treated with antibiotics. When a dominant stricture (a single tight narrowing) blocks a major bile duct, doctors can widen it during an endoscopic procedure, threading a balloon or stent through the duct to restore bile flow.
When Liver Transplant Becomes Necessary
Liver transplantation is the only treatment that can cure PSC, and it’s considered when the liver is failing or when complications become unmanageable. The standard scoring system used to prioritize transplant candidates (the MELD score) doesn’t always capture how sick a PSC patient is, because some of the worst complications, like recurrent infections or unbearable itching, aren’t reflected in blood tests.
For that reason, transplant centers may consider PSC patients for transplantation regardless of their MELD score if they’re experiencing intractable itching that destroys quality of life, or if they’ve been hospitalized for bacterial cholangitis two or more times within a year. Suspected or confirmed cholangiocarcinoma is another indication, though it requires a specialized treatment protocol before transplant.
Outcomes after transplant are generally good. PSC does recur in the transplanted liver in a portion of patients, but recurrence is usually slower and milder than the original disease.
Living With PSC
Because PSC progresses at very different rates from person to person, the day-to-day experience varies widely. Some people live for years with normal energy levels and minimal symptoms. Others deal with persistent fatigue and itching that interfere with sleep and daily functioning. Keeping up with the recommended surveillance schedule is one of the most important things you can do, since catching complications like dominant strictures or early-stage cancer significantly improves outcomes.
Bone thinning is another long-term concern, because impaired bile flow reduces the absorption of fat-soluble vitamins, including vitamin D. Many PSC patients are advised to supplement vitamin D and have periodic bone density checks. Maintaining a healthy diet, staying physically active, and avoiding alcohol (which adds additional stress to an already compromised liver) all help preserve liver function for as long as possible.