Hepatitis C is a viral infection that affects your liver, causing swelling and damage. Hepatitis C is transmitted through contact with the blood of a person who has hepatitis C — often through the use of unsterilized injection devices or shared needles.

When you contract the hepatitis C virus, your immune system activates to fight the virus until the infection is overcome.

A short-term hepatitis C infection may not have any long-term effects on your immune system. But a hepatitis C infection that lasts for 6 months or longer can cause your immune system to remain activated for too long.

An overactive immune system can lead to the development of an autoimmune condition, like rheumatoid arthritis, which happens when the immune system mistakenly attacks healthy tissue.

Read on to learn more about the effect of hepatitis C on your immune system, including possible long-term complications and how you can help prevent them.

In many cases, your immune system will be able to fight off an acute hepatitis C infection. When this happens, your immune system is unlikely to experience any lasting effects.

But if your immune system doesn’t adequately clear the acute hepatitis C infection, it becomes chronic. A chronic hepatitis C infection will affect your immune system.

During chronic hepatitis C, the virus is constantly replicating itself in your body and changing slightly with each replication to help itself resist your immune system. This activates your immune system for an extended period of time.

Constant, long-term immune system activation can disrupt the immune system’s natural ability to adapt to the viral presence in your body. It can also cause low level inflammation in your liver — which can cause irreversible damage and scarring.

Over time, hepatitis C can also damage your immune system and cause conditions that are related to how your immune system works. These conditions are called extrahepatic manifestations of hepatitis C, because they happen in places other than the liver. They can include:

  • Arthralgia: Arthralgia is a condition that causes joint pain and stiffness. Unlike arthritis, people with arthralgia don’t have any swelling or inflammation.
  • Nonspecific rheumatoid diseases: These are autoimmune conditions, such as vasculitis, that can happen when your immune system attacks the tissues surrounding your joints. It causes painful and stiff joints, fatigue, and fever.
  • Cryoglobulinemia: This condition is a type of vasculitis that happens when proteins in your blood called cryoglobulins stick together in chunks when your body temperature falls below the normal range. Over time, this can restrict your blood flow.
  • Lichen planus: This is a skin condition that can result in a rash of itchy light or dark lesions across the body, including inside the mouth.
  • Autoimmune thyroid disease: This can happen when your thyroid gland becomes inflamed (thyroiditis) or doesn’t produce hormones properly.
  • Autoimmune hemolytic anemia: This happens when your body doesn’t produce enough red blood cells to keep up with those that die naturally or are destroyed by your immune system.

Treating chronic hepatitis C early can help:

  • prevent damage to your liver
  • reduce immune system activation
  • lower your risk of developing conditions elsewhere in the body

But if chronic hepatitis is left untreated, damage can be permanent and much harder to manage. You might need additional treatment and therapies to address the symptoms caused by chronic hepatitis C.

Hepatitis is often linked with other liver conditions as well, including:

  • Cirrhosis: Cirrhosis happens when scar tissue replaces the healthy tissue in your liver. Over time, this blocks blood flow and makes it hard for your liver to function.
  • Liver cancer: Liver cancer is cancer that grows in your liver. Hepatitis C raises your risk for liver cancer.
  • Liver failure: Liver failure is also called end stage liver disease. It happens when the liver becomes too damaged to function normally. The only long-term treatment for liver failure is a liver transplant.

Hepatitis viral infections can be either acute or chronic:

  • Acute: These are short-term infections that last 6 months or less and don’t typically have any long-term effects on your immune system.
  • Chronic: This happens when your immune system can’t effectively mount an effective defense against the hepatitis C virus. Chronic hepatitis C can be serious and even life threatening.

Hepatitis C doesn’t always cause symptoms. The World Health Organization reports that about 80% of people who have acute hepatitis C infections never experience symptoms. And when symptoms do occur, they vary depending on whether the viral infection is acute or chronic.

Acute hepatitis C symptoms occur about 8 to 12 days after contact with the virus and can include:

Chronic hepatitis C symptoms can be less obvious, including:

  • fatigue
  • sleep disturbances
  • anorexia
  • arthralgia (joint pain)
  • weight loss with no obvious cause
  • feeling weak
  • feeling depressed
  • feeling anxious

If chronic hepatitis C causes liver scarring, you can also experience:

Seek treatment right away

An untreated hepatitis C infection can lead to serious complications and can be fatal. But with treatment, hepatitis C can often be resolved in 8 to 12 weeks.

See a medical professional right away if you think you’ve been exposed to the hepatitis C virus or have any symptoms of hepatitis C.

Since 2013, Hepatitis C has been treated with antiviral medications. These medications can successfully cure hepatitis C in most people in about 8 to 12 weeks. A doctor will closely monitor you during the treatment period to document when you’ve been cleared of the infection.

Hepatitis C medications work for both acute and chronic hepatitis C — but keep in mind that antiviral treatments will only work on chronic infections, not acute infections. Other treatments may also be used for side effects or complications of hepatitis C, but this can vary depending on the specific case.

For instance, additional treatments might address symptoms like pain and nausea or work to repair liver damage.

Although there are vaccines for other types of hepatitis, there’s currently no vaccine for hepatitis C.

But there are still steps you can take to reduce your risk of hepatitis, including:

  • Don’t share personal care items, such as razors or nail clippers, that could have someone else’s blood on them.
  • Don’t share or reuse needles for any type of injection.
  • Ensure that sterile needles are used at any tattoo or body piercing shop you visit.
  • Always wear gloves when you need to touch blood that isn’t yours.
  • Practice safer sex by always using condoms or other barrier methods and getting tested regularly for sexually transmitted infections (STIs).
  • Get tested for hepatitis C if you know or suspect you’ve been exposed.

Chronic hepatitis C can affect your immune system as the virus causes your immune system to become overactive.

In most cases, antiviral medications can cure hepatitis C in 8 to 12 weeks. But when hepatitis C goes untreated, it can lead to lasting liver damage and extrahepatic manifestations that can require additional treatments.

Get tested for hepatitis C any time you think you might have been exposed to the virus or any time you have symptoms that could be related to hepatitis C.