How Is Hepatitis C Diagnosed?

Hepatitis C is an inflammatory liver condition caused by the hepatitis C virus (HCV). About 3% of people in the world have this virus. Roughly 2.4 million people live with hepatitis C in the United States.

Hepatitis C is usually transmitted through contact with infected blood and blood products. This may include needle sharing, such as with drug injections, or from tattooing. While less common, it can also spread through unprotected sex, from a birthing parent with HCV to their baby while giving birth, and medical procedures with cross-contamination.

Your healthcare provider, such as a primary care doctor, can diagnose hepatitis C. After that, they may ask you to see a specialist, such as a hepatologist (a doctor who specializes in liver care), a gastroenterologist (a doctor specializing in digestive diseases), or an infectious disease expert.

Getting a Diagnosis

Your doctors will need to take your medical history, perform a physical exam, and request diagnostic tests to diagnose hepatitis C.

Medical History

A diagnosis usually begins with reviewing your medical history. Your healthcare provider will ask if you are experiencing any possible symptoms of hepatitis C, such as:

• Fatigue
• Malaise, a feeling of general discomfort 
• Weight loss
• Bleeding easily 
• Bruising easily 
• Itchy skin
• Jaundice, or yellowing of the eyes and skin
• Dark-colored urine
• Very light-colored poop
• Pain in your abdomen 
• Nausea and vomiting
• Joint pain 
• Swollen arms and legs

Many people with hepatitis C don't show any symptoms. Because of this, the U.S. Preventive Services Task Force recommends HCV screening for everyone aged 18-79 years, even if you don’t have any signs of liver disease.

Your healthcare provider will also want to know if you have a high risk for the condition. They may ask if you:

• Had any blood transfusions, shared injections, or medical procedures like dialysis or organ transplants
• Share personal items like razors, nail cutters, and clippers
• Work in a place where you are exposed to used needles and blood
• Were born to a birthing parent with hepatitis C
• Use injected drugs or have used them in the past 
• Have hemophilia, a condition that causes lack of blood clotting
• Have tattoos or piercings

Physical Examination

Along with asking about your history of possible symptoms, your healthcare provider may also examine you for signs of hepatitis C. Some things they’ll examine are your:

• Skin for changes in color, as well as spidery blood vessel patterns (called spider angioma)
• Arms and feet for signs of swelling 
• Abdomen for signs of tenderness, swelling, and enlarged organs

Blood Tests

After the physical exam, your doctor may request some tests that can identify hepatitis C in your blood. Each test will require a blood sample that is then examined in a lab. Some of these tests are:

Hepatitis C Antibody Test: This screening test detects HCV antibodies in your blood, which are specific proteins in your immune system. A positive antibody test means you have been exposed to HCV in the past: this could mean you either have a current infection or your body may have cleared the virus. Some people with HCV can clear the virus—or recover from it—either spontaneously without treatment or after taking treatments for HCV.

If your hepatitis C antibody test is positive, you’ll need a confirmatory test like the hepatitis C RNA test, which can determine if you currently have hepatitis C.

Hepatitis C RNA Test: This confirmatory test detects the RNA—a type of genetic material—from the hepatitis C virus. The hepatitis C RNA test can detect an ongoing hepatitis C infection and help estimate how much virus is in your blood (known as the viral load). This information can help your healthcare provider choose the best treatments for you and monitor how well the treatments are working.

Genotype Testing: There are seven major strains or genotypes of hepatitis C, named genotype 1–7. In the United States, genotype 1 is the most common strain, accounting for 60% or more of HCV cases. Genotype testing is a specific blood test that helps your healthcare provider determine the strain of HCV, which can help them tailor your treatments accordingly.

Hepatitis C Core Antigen Test: This test measures the hepatitis C core antigen in your blood. It is not as accurate as the HCV RNA test and may fail to detect mild infections or those with low viral levels. But where HCV RNA is unavailable, doctors may use it along with antibody testing to detect HCV infections.

Imaging Tests

Your doctors may also ask you to do some imaging tests to assess your liver and determine if there’s any damage.

• Magnetic resonance elastography (MRE):  This is a non-invasive test that combines magnetic resonance imaging (MRI) with an ultrasound to create a picture of your liver's health. This test can detect scarring of the liver (called fibrosis) due to chronic hepatitis C and other liver conditions. A common complication of long-term hepatitis C is cirrhosis, a severe stage of liver scarring.
• Transient elastography: This is another non-invasive test that uses ultrasound to assess the condition of your liver. A damaged liver will have some stiffness, which this test easily detects. 
• Liver biopsy: A liver biopsy can be used to examine your liver condition more closely. During the procedure, a healthcare provider will administer local anesthesia and insert a thin needle into your abdomen to take a small sample of liver tissue. This liver sample is taken for further testing in a lab.

Types of Hepatitis C

Aside from the specific genotype of HCV, the type of hepatitis C can vary by how long the condition lasts. It’s separated into two groups: acute (short-term) and chronic (long-term).

• Acute infection: All cases of HCV begin as acute infections. You could have a brief infection and your body eventually clears the virus—either on its own or with treatment. Between 15-45% of people with HCV clear the virus within 6 months, meaning their case stays acute.
• Chronic infection: The remaining people with HCV (55-85%) will have the virus for longer than 6 months, making it chronic. Your immune system may not be able to recover from the virus on its own. However, a healthcare provider can prescribe antiviral treatments, which can prevent worsening symptoms and in some cases, help clear the virus. Chronic hepatitis C may become a lifelong condition.

Research suggests that chronic HCV infections are more likely to get worse in people who also have:

• Alcohol use disorder
• Cirrhosis, or severe scarring of the liver 
• Hepatitis B, or liver inflammation that is caused by the hepatitis B virus (HBV)

If not treated, chronic HCV infections can lead to permanent liver damage, seen in conditions like cirrhosis, liver cancer, and liver failure.

Screening for Related Conditions

Several diseases of the digestive system—especially liver conditions—have similar symptoms as hepatitis C. Your healthcare provider will also want to check for any of the following conditions.

Other liver conditions with similar symptoms to hepatitis C include:

• Other viral hepatitis, such as hepatitis A, B, D and E
• Drug-induced liver injury, or liver damage associated with drug use 
• Alcoholic liver disease, or liver damage due to excess alcohol use
• Autoimmune hepatitis, caused by the immune system attacking liver tissue
• Liver cancer, of which hepatocellular carcinoma is a common type and complication of HCV
• Liver abscess, a pus-filled pocket due to infection or injury

Your doctors can tell the difference between a hepatitis C infection and other liver diseases using hepatitis C screening and imaging tests.

Conditions That May Coexist With Hepatitis C

People with hepatitis C are more likely to have another disease or more than two diseases at the same time.

After an HCV diagnosis, your healthcare provider may check if you have any other conditions that are commonly associated with hepatitis C. Some conditions include:

• Human immunodeficiency virus (HIV): About 4% of people with HCV may also have HIV. Having both HCV and HIV can increase your risk of severe liver damage. Your healthcare provider may order an HIV test to confirm your status.
• Depression: Research suggests that depression is common in people with HCV, especially those with a history of drug injections. If your doctor suspects you have depression, they may refer you to a mental health professional for further care.
• Diabetes: HCV is more common in people with type 2 diabetes, and HCV is associated with a greater risk of developing type 2 diabetes. Your doctor may ask you to do a fasting blood sugar test to check for raised blood sugar levels.
• Non-liver cancers: Besides liver cancer, researchers have also observed higher rates of other cancers in people with HCV. These include cancers of the lungs, pancreas, mouth, throat, and anus.

A Quick Review

Hepatitis C is a contagious viral disease that can cause permanent liver damage. To diagnose hepatitis C, your healthcare provider will need your medical history, a physical examination, and additional tests, such as blood tests.

Imaging tests may be done to determine any liver damage. Your doctor may also order other tests to rule out other conditions with symptoms that are similar to those of hepatitis C. If you do have HCV, your healthcare provider can also check if you have other conditions commonly associated with hepatitis C, such as diabetes, HIV, depression, and certain cancers.