Hepatitis D is a virus that causes an infection only in people who already have hepatitis B or who contract hepatitis D and B at the same time. 

According to the World Health Organization (WHO), it affects nearly 5% of people worldwide who already have hepatitis B. A healthcare provider who suspects a hepatitis D infection usually will use basic blood tests to confirm a diagnosis. 

This article will take a closer look at how healthcare providers typically diagnose hepatitis D. 

Self-Checks

The symptoms of hepatitis D may not be all that obvious and can mimic the symptoms of other conditions. You may not have any symptoms at all during the acute phase of the disease. 

Symptoms may include:

• Fever
• Nausea
• Fatigue
• Jaundice (yellowing of the skin and whites of the eyes)
• Malaise (a general feeling of being unwell)
• Abdominal pain in the upper-right area, near the liver
• Dark-colored urine 
  

A chronic hepatitis D infection happens when your body is unable to fight the infection. Often, the first sign of chronic hepatitis D involves symptoms of liver damage.

Symptoms may include:

• Jaundice
• Fatigue
• Redness on the palms
• Spider veins (visible clusters of small, superficial veins)
• Swelling of the abdomen
• Difficulty concentrating
  

If you’re experiencing a combination of these symptoms, consider making an appointment with your healthcare provider. 

Physical Examination

If your healthcare provider is already aware that you have an existing hepatitis B infection, they may suspect a new hepatitis D infection if your symptoms suddenly get worse. 

Some physical signs to be on the lookout for include:

• Jaundice
• Redness on your palms
• The presence of spider veins 
• Abdominal swelling that may indicate problems with your liver or spleen 

They may also ask you questions to determine whether you’re at risk for a hepatitis B or D infection, such as:

• Have you recently traveled to a place where hepatitis B or D is common?
• Are you an intravenous drug user?
• Do you have HIV (human immunodeficiency virus)?
• Are you a man who has sex with men?
• Have you been vaccinated for hepatitis B?

Labs and Tests 

Healthcare providers use various tests to help diagnose hepatitis D. 

Blood Tests

The following blood tests can be used to make a hepatitis D diagnosis:

• Hepatitis B tests: If you have not already been diagnosed with hepatitis B, this test may be performed.
• Hepatitis D total antibody test: This test checks for the presence of antibodies produced in response to a hepatitis D infection, including immunoglobulin M (IgM) and immunoglobulin G (IgG). This test can confirm the presence of a hepatitis D infection and whether the infection is chronic or acute.
• Hepatitis D RNA quantitative polymerase chain reaction (PCR) test: Healthcare providers use this test if your antibody test is positive. It’s another way to confirm a hepatitis D diagnosis and determine whether the infection is active or not.

Other Tests

The tests mentioned above are the primary ways healthcare providers confirm a hepatitis D infection. The following tests may help determine whether you’re responding to treatment:

• Fibroscan: This ultrasound technology helps healthcare providers monitor your liver and check for potential damage.
• Liver function tests (LFTs): This panel of blood tests for liver enzymes and proteins monitors liver function and checks for liver injury. 
• Platelet count: This blood test (if the count is low) can indicate you have portal hypertension, a complication that may arise due to liver scarring.
  

Differential Diagnosis 

It’s crucial that healthcare providers perform tests to rule out other diagnoses (a process called differential diagnosis), especially since hepatitis D symptoms are the same as other forms of viral hepatitis. 

Symptoms of chronic hepatitis D can also mimic:

• Hepatitis A, B, C, or E: Different types of viral hepatitis
• Alcoholic hepatitis: Inflammation of the liver due to drinking too much alcohol
• Liver abscess: A walled-off area of pus in the liver
• Autoimmune hepatitis: Your immune system mistakenly attacks your liver 
• Budd-Chiari syndrome: A blockage in the hepatic veins that drain the liver causes a backup of blood in the liver
• Cholecystitis: Inflammation of the gallbladder
• Cholangitis: Infection of the bile ducts

Summary 

Hepatitis D is sometimes difficult to diagnose because people may not have symptoms when they first contract the virus. Some people may experience only vague symptoms like malaise and fatigue, making it hard to pinpoint a diagnosis.

Sometimes, physical signs of hepatitis D, like yellowed skin and belly swelling, can be a clue to a diagnosis. But a physical exam isn't enough to confirm a diagnosis since there is an overlap of symptoms between different types of viral hepatitis. To diagnose hepatitis D, healthcare providers use blood tests, including antibody and PCR testing. 

A Word From Verywell

If you think you may have hepatitis D, it’s essential to make an appointment with a healthcare provider to confirm a diagnosis. Promptly treating the condition can help prevent complications and limit liver damage in the long run.