Hepatitis C is a viral infection that can cause serious liver damage. Research suggests that more than 2 million American adults have hep C, but the real number is probably much higher. About half of people with hep C have no clue they’ve got it, because this virus often sneaks in without symptoms.

The virus spreads through blood-to-blood contact, such as sharing a needle or syringe with someone who has hep C when injecting drugs or getting a tattoo in a less-than-clean shop. In rare cases, the virus can pass from person to person during sex — but only if there’s blood involved. You can’t get hep C from kissing someone or taking a sip of your friend’s beer.

Hep C is a big deal because it can damage your liver. You need your liver to make digestive fluid, get rid of toxins, and do other important stuff. Without treatment, hep C can progress to cirrhosis, liver cancer, and eventually liver failure.

But we do have medications that can cure most cases of hep C. They’re called direct acting antivirals (DAAs), and they make it pretty easy for doctors to treat the virus. Basically, you take the pills every day for about 3 months and you’re done.

This alphabet soup of viruses can be confusing. Hepatitis A, B, and C all cause liver disease, but they differ in the ways they spread and are treated.

Hepatitis A spreads through poop-contaminated foods and drinks. You can get it if someone with the virus goes to the bathroom and doesn’t wash their hands before they cook your meal. This virus can also spread through sex if people don’t use condoms or another barrier method.

There’s no treatment for hep A, but there is a vaccine to prevent it. And most people who get hep A recover in a few weeks or months without treatment.

Hepatitis B spreads through contact with the bodily fluids — such as blood and semen — of someone who has it. It can be transmitted through sex or sharing needles and syringes to inject drugs, and it can pass from a pregnant person to a baby during childbirth. There is a hep B vaccine, and antiviral meds can treat the infection.

Hepatitis C spreads through blood, usually when people share needles and syringes to inject drugs. There’s no vaccine for hep C. Some people’s bodies get rid of the virus without treatment, and in most cases where that doesn’t happen, DAAs can cure the infection.

Yes. Antibodies are proteins your body makes to attack a virus. If you test positive for hep C antibodies, it means you’ve had hep C at some point in your life. After a positive antibody test, you can get a viral load or RNA PCR test to find out whether:

  • you have an acute infection, which means you picked up the virus in the last 6 months
  • you have a chronic (long-term) infection that you got more than 6 months ago
  • you had hep C at some point in your life, but it’s not active anymore

Since Hep C is transmitted through bodily fluids, there are six main ways of contracting it:

  • by sharing needles, syringes, or other drug injection equipment — this is the main way hep C spreads today
  • during pregnancy and childbirth — about 6% of babies whose moms have hep C will get the virus
  • by getting stuck with a needle that carries the virus while working in a doctor’s office, clinic, or hospital
  • by having sex — this risk is highest in men who have sex with men
  • by getting a tattoo or body piercing in an unlicensed shop that doesn’t use clean needles and ink
  • by sharing personal items such as nail clippers, razors, or toothbrushes with someone who has the virus, if it involves blood-to-blood contact

The virus used to spread through blood transfusions and organ transplants too. But the blood supply has been screened for the virus since 1992, so this mode of transmission rarely happens today.

An acute hep C infection can be contagious for 1 week or longer before symptoms show up. Chronic hep C stays contagious until it’s cured. Lots of people have no symptoms early on, and they can transmit the virus without knowing it.

If you test positive for the virus, consider it contagious until you get a negative RNA PCR test result. Until you’re sure about your hep C status, you can take precautions — such as using condoms during sex and avoiding sharing personal items like toothbrushes or nail clippers — to avoid exposing anyone else to the virus.

That depends on your situation and where you live. You don’t have to disclose that you have hep C to an employer. But in these nine states, you could go to jail if you knowingly expose someone to the virus through sex, needle sharing, or bodily fluids such as saliva:

  • Indiana
  • Iowa
  • Mississippi
  • Nebraska
  • North Carolina
  • Ohio
  • Pennsylvania
  • Tennessee
  • Utah

There’s no question that a hep C vaccine would come in handy. About 71 million people worldwide have the virus, and it kills at least 400,000 people each year. We’ve had vaccines against hepatitis A and B for decades, but the development of a hepatitis C virus has been much slower.

One reason for the delay is that hep C comes in at least 8 varieties, called genotypes, and 86 subtypes. We’d need a different vaccine to target each type.

Plus, hep C is a shape-shifter. It constantly mutates, and that makes it hard to target with a vaccine. On top of that, drug companies don’t want to invest money to research a vaccine since current treatments can cure more than 90% of hep C cases.

Hepatitis C is a liver infection that can cause cirrhosis, liver cancer, and liver failure. It spreads through blood-to-blood contact, most often through sharing needles to inject drugs.

You can have hep C — and spread it — without showing any symptoms. That’s why the Centers for Disease Control and Prevention recommends that every adult get tested at least once in their life. People who are at higher risk of contracting the virus — including anyone who injects drugs and shares needles — may need to get tested more often.