Hepatitis C is a viral infection that attacks the liver, often silently causing damage over decades before symptoms appear. An estimated 69,000 new infections occurred in the United States in 2023 alone, and many people living with the virus don’t know they have it. The good news: hepatitis C is now curable in more than 95% of cases with a short course of oral medication.
How Hepatitis C Infects the Liver
The hepatitis C virus (HCV) is a blood-borne pathogen. Once it enters your bloodstream, it targets liver cells. The virus attaches to the surface of a liver cell, gets pulled inside, and releases its genetic material into the cell’s machinery. That genetic material hijacks the cell’s protein-building equipment to produce new copies of itself. Those copies get packaged up, released back into the bloodstream, and go on to infect more liver cells.
The liver damage from hepatitis C isn’t primarily caused by the virus destroying cells directly. Instead, your immune system sends inflammatory cells into the liver to fight the infection. These immune cells, many of which aren’t even targeting the virus specifically, cause collateral damage to healthy liver tissue. Over time, this chronic inflammation leads to scarring.
How It Spreads
Hepatitis C spreads through direct contact with infected blood. The most common route is sharing needles, syringes, or other equipment used to inject drugs. This includes people who injected drugs even once, years or decades ago.
Less common routes include:
- Childbirth: a mother with HCV can pass it to her baby during delivery
- Sexual contact: possible but relatively inefficient
- Tattoos or piercings done in unregulated settings with unsterilized equipment
- Shared personal items that may carry traces of blood, like razors or toothbrushes
- Healthcare exposures: needlestick injuries or accidental contact with infected blood
Blood transfusions and organ transplants were a significant source of infection before 1992, when routine screening of the blood supply began. Anyone who received a transfusion, blood products, or an organ transplant before July 1992 has an elevated risk. The same applies to people who received clotting factor concentrates before 1987.
You cannot get hepatitis C from casual contact, sharing food, coughing, sneezing, or hugging.
Acute vs. Chronic Infection
When someone first contracts hepatitis C, they enter what’s called the acute phase, which covers roughly the first six months. Most people have no symptoms during this period. An estimated 15 to 45% of people will clear the virus on their own during this window, without any treatment. Genetic factors play a significant role in whether someone clears the virus naturally. In one study, people with a certain genetic variant cleared the virus 53% of the time, while those with a different variant cleared it only 23% of the time.
The remaining 55 to 85% of people who don’t clear the virus develop chronic hepatitis C, a long-term infection that persists unless treated. Chronic infection is where the real danger lies, because the virus quietly damages the liver over years and decades.
Symptoms and Effects Beyond the Liver
Hepatitis C is sometimes called a “silent” infection because most people feel fine for years. When symptoms do appear in chronic infection, they tend to be vague: fatigue, joint pain, muscle aches, and general weakness. These can easily be attributed to other causes, which is one reason so many infections go undiagnosed.
The virus doesn’t just affect the liver. Chronic HCV triggers abnormal immune responses throughout the body. One of the more common complications involves a condition where abnormal proteins clump together in the blood, causing a classic triad of symptoms: a purplish skin rash (usually on the legs), muscle pain, and joint pain. This same process can damage the kidneys, causing inflammation that shows up as blood or protein in the urine.
People with chronic hepatitis C also face a higher risk of certain blood cancers, particularly types of non-Hodgkin lymphoma. The virus can trigger the body to produce various autoantibodies, proteins that mistakenly attack your own tissues, which may contribute to thyroid problems and other autoimmune-like symptoms.
Long-Term Liver Damage
Left untreated, chronic hepatitis C slowly scars the liver. An estimated 20 to 30% of people with chronic infection will develop cirrhosis over a 25- to 30-year period. Cirrhosis means the liver has accumulated so much scar tissue that its structure and function are compromised.
Once cirrhosis develops, the risks escalate. Each year, 2 to 5% of people with cirrhosis will experience decompensation, meaning the liver can no longer keep up with the body’s needs. This can cause fluid buildup in the abdomen, internal bleeding, confusion from toxin buildup, and jaundice. Liver cancer develops in 1 to 4% of cirrhosis patients per year. These complications are the primary reasons hepatitis C remains a serious public health concern, and why early detection and treatment matter so much.
Who Should Get Tested
The U.S. Preventive Services Task Force recommends that all adults aged 18 to 79 get screened for hepatitis C at least once. For most people, a single test is enough. If you have ongoing risk factors, such as current or past injection drug use, periodic retesting is recommended. Clinicians may also consider screening people younger than 18 or older than 79 who have specific risk factors.
Other groups that should be tested include people living with HIV, anyone who has received long-term hemodialysis, healthcare workers who’ve had a needlestick exposure, and infants born to mothers with hepatitis C.
How Testing Works
Diagnosis follows a two-step process. The first test checks for HCV antibodies in your blood. Antibodies are proteins your immune system produces in response to the virus. A negative antibody test generally means you’ve never been infected, as long as you haven’t had a potential exposure in the last six months (it takes time for antibodies to develop).
A positive antibody test doesn’t necessarily mean you’re currently infected. It means your body encountered the virus at some point. To determine whether you have an active infection, a second test checks for the virus’s genetic material (HCV RNA) in your blood. If both the antibody test and the RNA test come back positive, you have an active infection that needs treatment. If the antibody test is positive but the RNA test is negative, you were exposed at some point but your body cleared the virus, either on its own or through past treatment.
In cases of very recent exposure, the antibody test can be negative while the RNA test is positive. This indicates a brand-new infection that your immune system hasn’t fully responded to yet.
Treatment and Cure
Hepatitis C is one of the few chronic viral infections that modern medicine can actually cure. Treatment uses a class of medications called direct-acting antivirals, or DAAs, which target specific steps in the virus’s ability to replicate inside your cells. These medications are taken as pills, typically for 8 to 12 weeks.
Cure rates exceed 95%. A cure is confirmed when no viral genetic material is detectable in your blood 12 weeks after finishing treatment. At that point, the infection is gone. Older treatments involved interferon injections with significant side effects and much lower success rates. Current DAA regimens are far better tolerated and far more effective.
Treatment can’t reverse cirrhosis that has already developed, though it does halt further virus-driven damage. This is why catching the infection early, before extensive scarring occurs, leads to the best long-term outcomes. People who are cured and don’t yet have significant liver damage can expect a normal life expectancy.