Hepatitis C is a viral infection that damages the liver

Hepatitis C is caused by the hepatitis C virus (HCV), which attacks liver cells and causes inflammation. The virus spreads through blood-to-blood contact, most commonly when people share needles or other equipment used to inject drugs. You cannot catch hepatitis C from food, water, casual contact, or sharing utensils—the virus needs direct access to the bloodstream.

Most people infected with hepatitis C do not feel sick at first. Some have no symptoms for years, even as the virus quietly damages their liver. Others develop flu-like symptoms within weeks: fatigue, joint pain, fever, or yellowing of the skin and eyes. The problem is that without treatment, about 75 to 85 out of every 100 people who get infected develop chronic hepatitis C, meaning the virus stays in their body long-term and continues harming the liver.

Key Takeaways

  • Hepatitis C spreads through blood-to-blood contact, most often when people share needles or drug-injection equipment.
  • Most people have no symptoms when first infected, so many do not know they carry the virus until they are tested.
  • Without treatment, chronic hepatitis C can lead to cirrhosis (severe scarring of the liver) and liver cancer over 10 to 40 years.
  • Modern antiviral medications cure hepatitis C in 8 to 12 weeks for most people, even those with advanced liver damage.
  • A single blood test can detect whether you have hepatitis C or have been exposed to it in the past.

How the virus enters your body and spreads

Hepatitis C virus lives in blood. It enters your bloodstream when infected blood contacts an open wound, cut, or mucous membrane. The most common route today is sharing needles, syringes, or other equipment used to prepare or inject drugs. Sharing straws for snorting drugs, tattoo needles, or body-piercing equipment that was not properly sterilized also carries risk. Healthcare workers can be exposed through needle-stick injuries, though this is rare in modern settings with standard precautions.

Before 1992, hepatitis C spread through blood transfusions because donated blood was not screened for the virus. That risk is now extremely low in countries with routine blood screening. Hepatitis C does not spread through saliva, so kissing an infected person carries no risk. It does not spread through breast milk, though breastfeeding is safe unless the mother's nipples are cracked and bleeding.

A pregnant woman with hepatitis C can pass the virus to her baby during delivery, though this happens in only about 5 out of every 100 pregnancies. Babies born to mothers with hepatitis C are tested and monitored, and most clear the infection on their own within the first year of life.

What happens to your liver over time

When hepatitis C virus enters your liver, it begins replicating inside liver cells. Your immune system responds with inflammation, which is your body's attempt to fight the infection. In some people—about 15 to 25 out of every 100—the immune system clears the virus on its own within six months. These people develop immunity and cannot be reinfected.

In the majority of people, the virus persists. The ongoing inflammation causes liver cells to die and be replaced by scar tissue, a process called fibrosis. Over years or decades, fibrosis can progress to cirrhosis, where so much of the liver is scarred that it cannot function properly. Cirrhosis can lead to liver failure, internal bleeding, fluid buildup in the abdomen, confusion from toxins the liver cannot filter, and liver cancer.

The timeline varies widely. Some people develop cirrhosis within 10 years; others take 40 years or more. Factors that speed progression include heavy alcohol use, infection with HIV or hepatitis B at the same time, being male, and being older when infected. Having hepatitis C does not automatically mean you will develop cirrhosis, especially if you receive treatment before significant scarring occurs.

Testing and diagnosis

A blood test is the only way to know whether you have hepatitis C. The test looks for antibodies to the virus (which your immune system makes in response to infection) or for the virus itself. If you test positive for antibodies, a second test called an HCV RNA test determines whether you currently have the virus or cleared it in the past.

The Centers for Disease Control and Prevention (CDC) recommends that all adults get tested for hepatitis C at least once in their lifetime. People with higher risk—including those with a history of injection drug use, those who received a blood transfusion before 1992, or healthcare workers—may be tested more frequently. If you are pregnant, testing is part of routine prenatal care.

If you test positive, your doctor will order additional tests to check how well your liver is working and whether cirrhosis is present. These may include blood tests that measure liver function and imaging studies like ultrasound or elastography (a test that measures liver stiffness). These results help determine whether you need treatment right away or can wait.

How modern treatment works

Hepatitis C is now curable. Direct-acting antiviral (DAA) medications target specific parts of the virus and stop it from replicating. These drugs are taken by mouth for 8 to 12 weeks, depending on which medication your doctor prescribes and the specific strain of virus you have. Most people tolerate them well, with few side effects.

Cure rates are very high—above 95 percent for most people, even those with cirrhosis. Treatment works regardless of how long you have had the virus or how much liver damage has occurred. If your liver has already developed cirrhosis, treatment can stop further damage and sometimes allow some scarring to improve, though it cannot reverse cirrhosis completely.

The main barrier to treatment is access. In many countries, DAA medications are expensive, though prices have dropped significantly since they were first introduced. Some insurance plans cover them; others require proof of liver damage or abstinence from alcohol before they will pay. State and federal programs, as well as pharmaceutical assistance programs, help people without insurance or with limited coverage.

Living with hepatitis C before and after treatment

If you have hepatitis C and have not yet been treated, protecting your liver means avoiding alcohol (which speeds liver damage), maintaining a healthy weight, and getting vaccinated against hepatitis A and B if you are not already immune. Regular check-ups with a doctor who specializes in liver disease help monitor your condition.

After successful treatment, you are cured—the virus is gone and cannot return. However, you can be reinfected if you are exposed to the virus again through blood contact. People who were infected through injection drug use and continue using drugs face this risk. Cure does not create immunity the way clearing the virus naturally does.

If your liver has cirrhosis, monitoring continues even after cure. Your doctor will screen for liver cancer with ultrasound and blood tests, usually every six months. Some people with cirrhosis also need screening for internal bleeding from enlarged veins in the esophagus. These precautions catch problems early when treatment is most effective.

Frequently Asked Questions

Can you get hepatitis C from sharing a toothbrush or razor?

Only if the toothbrush or razor causes bleeding in both people and infected blood from one person enters the bloodstream of the other. This is theoretically possible but extremely rare. Hepatitis C requires direct blood-to-blood contact, not just contact with saliva or skin.

If I was exposed to hepatitis C, how long before I test positive?

Antibodies usually appear within 4 to 10 weeks after infection. The virus itself (detected by HCV RNA test) can be found within 1 to 2 weeks. If you were exposed, ask your doctor when to be tested; testing too early may give a false negative result.

Does hepatitis C treatment cure the virus permanently?

Yes. After completing treatment and testing negative for the virus, you are cured and the virus will not return. However, you can be reinfected if exposed to the virus again through blood contact, so the risk depends on your behavior after treatment.

Can you donate blood or organs if you have had hepatitis C?

Blood banks do not accept donations from people with current or past hepatitis C infection. Organ donation is possible only in specialized circumstances and requires discussion with a transplant center. Policies vary by country and organization.

What should I do if I think I was exposed to hepatitis C?

Contact your doctor or visit an urgent care clinic. They can test you and, if needed, discuss whether post-exposure monitoring or early treatment is recommended. Do not wait for symptoms to appear—testing is the only way to know your status.