More than half the people with primary biliary cholangitis do not have any noticeable symptoms when diagnosed. The disease may be diagnosed when blood tests are done for other reasons. Symptoms eventually develop over the next five to 20 years. Those who do have symptoms at diagnosis typically have poorer outcomes.

Common early symptoms include:

• Fatigue
• Itchy skin
• Dry eyes and mouth

Later signs and symptoms may include:

• Pain in the upper right abdomen
• Swelling of the spleen
• Bone, muscle or joint (musculoskeletal) pain
• Swollen feet and ankles (edema)
• Buildup of fluid in the abdomen due to liver failure (ascites)
• Fatty deposits (xanthomas) on the skin around the eyes, eyelids or in the creases of the palms, soles, elbows or knees
• Yellowing of the skin and eyes (jaundice)
• Darkening of the skin that's not related to sun exposure (hyperpigmentation)
• Weak and brittle bones (osteoporosis), which can lead to fractures
• High cholesterol
• Diarrhea, which may include greasy stools (steatorrhea)
• Underactive thyroid (hypothyroidism)
• Weight loss

It's not clear what causes primary biliary cholangitis. Many experts consider it an autoimmune disease in which the body turns against its own cells.

The liver inflammation seen in primary biliary cholangitis starts when certain types of white blood cells called T cells (T lymphocytes) start to collect in the liver. Normally, these immune cells detect and help defend against germs, such as bacteria. But in primary biliary cholangitis, they mistakenly destroy the healthy cells lining the small bile ducts in the liver.

Inflammation in the smallest ducts spreads and eventually damages other cells in the liver. As the cells die, they're replaced by scar tissue (fibrosis) that can lead to cirrhosis. Cirrhosis is scarring of liver tissue that makes it difficult for your liver to work properly.

The following factors may increase your risk of primary biliary cholangitis:

• Sex. Most people with primary biliary cholangitis are women.
• Age. It's most likely to occur in people 30 to 60 years old.
• Genetic factors. You're more likely to get the condition if you have a family member who has or had it.
• Geography. It's most common in northern Europe and North America.

Researchers think that genetic factors combined with certain environmental factors trigger primary biliary cholangitis. These environmental factors may include:

• Infections caused by bacteria, fungi or parasites
• Smoking
• Toxic chemicals

As liver damage worsens, primary biliary cholangitis can cause serious health problems, including:

• Liver scarring (cirrhosis). Cirrhosis makes it difficult for your liver to work and may lead to liver failure. It indicates the later stage of primary biliary cholangitis. People with primary biliary cholangitis and cirrhosis have a poor prognosis and higher risk of other complications.
• Increased pressure in the portal vein (portal hypertension). Blood from your intestine, spleen and pancreas enters your liver through a large blood vessel called the portal vein. When scar tissue from cirrhosis blocks normal blood flow through your liver, blood backs up. This causes increased pressure inside the vein. Also, because blood doesn't flow normally through your liver, drugs and other toxins aren't filtered properly from your bloodstream.
• Enlarged spleen (splenomegaly). Your spleen can become swollen with white blood cells and platelets because your body no longer filters toxins out of the bloodstream as it should.
• Gallstones and bile duct stones. If bile cannot flow through the bile ducts, it may harden into stones, causing pain and infection.
• Enlarged veins (varices). When blood flow through the portal vein is slowed or blocked, blood may back up into other — usually those in your stomach and esophagus. Increased pressure may cause delicate veins to break open and bleed. Bleeding in the upper stomach or esophagus is a life-threatening emergency that requires immediate medical care.
• Liver cancer. Liver scarring (cirrhosis) increases your risk of liver cancer.
• Weak bones (osteoporosis). People with primary biliary cholangitis have an increased risk of weak, brittle bones that may break more easily.
• Vitamin deficiencies. A lack of bile affects your digestive system's ability to absorb fats and the fat-soluble vitamins, A, D, E and K. Because of this, some people with advanced primary biliary may have low levels of these vitamins.
• Decreased mental function (hepatic encephalopathy). Some people with primary biliary cholangitis with liver failure have personality changes and problems with memory and concentration.
• Increased risk of other disease. Primary biliary cholangitis is associated with metabolic or immune system disorders, including thyroid problems, limited scleroderma (CREST syndrome) and rheumatoid arthritis.