Multiple steps will be used to diagnose various types of hepatitis. A physician will compile a medical history, noting potential risk factors such as international travel or multiple sexual partners. A physical examination may indicate signs that the liver is enlarged or tender. Although some patients will experience symptoms, many others will not. As a result, blood testing is an important way of diagnosing viral hepatitis. Blood tests that reveal high levels of the pigment bilirubin (which may not be metabolized properly by a liver affected by hepatitis) and enzymes known as aminotransferases (released by the liver when it is damaged) may indicate the presence of hepatitis. 

A blood test can help pinpoint the exact type of hepatitis that is present. If a person is infected with viral hepatitis, a blood test will usually reveal the presence of antigens (for acute infections) unique to a certain type of virus and the antibodies to the specific virus that have formed in the body. However, antibodies sometimes do not appear until weeks or months after infection, so taking the test too early may produce a false-negative result.

Chronic hepatitis may be partially detected through a patient’s symptoms and liver function tests. However, a liver biopsy is necessary to determine the severity of the disease. In this procedure, a sample of liver tissue is obtained - usually with the aid of an ultrasound or computed axial tomography (CAT) scan of the abdomen - and analyzed under a microscope to look for signs of inflammation and scarring that might indicate cirrhosis.

In most cases, acute forms of viral hepatitis (A, B, C and E) resolve without treatment. However, chronic hepatitis (B, C and D) requires treatment with various forms of medication. People with chronic Hepatitis C should have their blood monitored for any changes in the number of viral particles. When the number becomes very high, indicating they have a substantial amount of virus present, they will require treatments. These treatments are available in injection and pill form and may last several weeks or several months, with the nature of the treatment dependent upon the severity of infection. It is important to note that not every patient is a candidate for treatment, and the need for treatment is determined by a patient's physician.

Although there is no cure for these forms of hepatitis, medications can reduce copies of the virus to the point that they are undetectable. If the virus remains undetectable for six months after treatment is finished, the patient is considered to have a sustained virologic response and is unlikely to experience further liver problems. New drugs and drug combinations are being developed to help treat chronic hepatitis in individuals who do not respond to traditional hepatitis medications.

In extreme cases, damage to the liver may be so great that a liver transplant may be necessary. Patients with some forms of hepatitis may be unsuitable transplant candidates. For hepatitis B patients, a transplanted liver will probably become reinfected with the virus. Hepatitis C patients may also be reinfected, but the recurrence is mild and may not seriously damage the new liver for many years.