Hepatitis B: Symptoms, Causes & Treatment Options

What Is Hepatitis B and How Does It Affect the Liver?

Hepatitis B is a viral infection caused by the hepatitis B virus (HBV) that primarily attacks the liver. It causes inflammation that can range from mild illness lasting a few weeks to a serious lifelong condition. Hepatitis B can be either acute (short-term, lasting less than 6 months) or chronic (long-term, lasting more than 6 months).

The hepatitis B virus belongs to the Hepadnaviridae family and has a remarkably stable structure that allows it to survive outside the body for up to seven days on surfaces. This makes it highly infectious - approximately 50 to 100 times more infectious than HIV. When the virus enters the body, it travels to the liver where it infects hepatocytes (liver cells) and begins replicating. The body's immune response to this infection causes inflammation, which can damage the liver over time.

Understanding the difference between acute and chronic hepatitis B is essential for patients and their families. Acute hepatitis B refers to the initial infection period, typically lasting less than six months. During this time, the immune system works to eliminate the virus. Most healthy adults successfully clear the infection, develop protective antibodies, and become immune for life. However, about 5-10% of infected adults, and up to 90% of infected infants, fail to clear the virus and develop chronic infection.

Chronic hepatitis B occurs when the immune system cannot eliminate the virus within six months. The virus persists in the liver, continuing to replicate and potentially causing ongoing damage. People with chronic hepatitis B may feel completely healthy for years or even decades, but the virus silently damages liver tissue. Over time, this can lead to serious complications including liver fibrosis (scarring), cirrhosis, and hepatocellular carcinoma (liver cancer).

The global burden of hepatitis B is substantial. According to the World Health Organization (WHO), approximately 296 million people worldwide were living with chronic hepatitis B infection in 2019, with 1.5 million new infections occurring each year. The disease causes approximately 820,000 deaths annually, primarily from cirrhosis and primary liver cancer. While hepatitis B is found worldwide, prevalence is highest in the Western Pacific and African regions, where 6.2% and 6.1% of the adult population are infected, respectively.

The Four Phases of Chronic Hepatitis B

Chronic hepatitis B infection typically progresses through four distinct phases, though not all patients experience every phase. Understanding these phases helps doctors determine the appropriate timing for treatment:

• Immune tolerant phase: High viral load but minimal liver inflammation. The immune system "tolerates" the virus. Most common in those infected at birth.
• Immune active phase: The immune system begins attacking infected liver cells, causing inflammation and elevated liver enzymes. Treatment is often recommended during this phase.
• Inactive carrier phase: Low or undetectable viral load with normal liver enzymes. The virus is controlled but not eliminated.
• Reactivation phase: The virus may reactivate, especially if the immune system becomes weakened. Regular monitoring is essential.

What Are the Symptoms of Hepatitis B?

Hepatitis B symptoms vary widely - many people have no symptoms at all, especially in the early stages or with chronic infection. When symptoms do occur, they typically appear 2-6 months after exposure and may include fatigue, loss of appetite, nausea, abdominal pain, dark urine, pale stools, and jaundice (yellowing of skin and eyes).

One of the most challenging aspects of hepatitis B is that many infected individuals remain completely asymptomatic. Among adults who develop acute hepatitis B, only about 30-50% experience noticeable symptoms. Children under five years old rarely develop symptoms, which unfortunately means the infection often goes undetected until serious liver damage has occurred. This "silent" nature of the disease makes testing particularly important for people at risk.

When symptoms do develop in acute hepatitis B, they typically follow a predictable pattern. The initial phase, often called the prodromal phase, includes non-specific symptoms that can easily be confused with other viral infections. Patients commonly experience profound fatigue that can be debilitating, general malaise, mild fever, headaches, and muscle or joint aches. These symptoms can last from several days to several weeks and may be accompanied by a loss of appetite, nausea, and occasionally vomiting.

Early Warning Signs

The earliest symptoms of hepatitis B often mimic a common flu-like illness. These include:

• Extreme fatigue: Profound tiredness that doesn't improve with rest, often lasting weeks to months
• Low-grade fever: Temperature slightly elevated, typically around 37.5-38.5°C (99.5-101.3°F)
• Loss of appetite: Decreased interest in food, often with nausea after eating
• Nausea and vomiting: May be persistent and worsen after fatty foods
• Joint and muscle pain: Can affect multiple joints, sometimes mimicking arthritis
• Skin rash: Some patients develop hives or a measles-like rash

Classic Hepatitis Symptoms (Icteric Phase)

After the initial prodromal phase, which typically lasts one to two weeks, patients may enter the icteric (jaundice) phase. This is when the more characteristic symptoms of hepatitis appear:

Jaundice is perhaps the most recognizable sign of hepatitis B. The yellowing occurs first in the whites of the eyes (sclera), then spreads to the skin. This discoloration happens because the inflamed liver cannot properly process bilirubin, a yellow pigment produced when red blood cells break down. Bilirubin accumulates in the blood and deposits in tissues, causing the characteristic yellow color. In people with lighter skin, this may appear as a yellow-orange tint, while in those with darker skin, it may be more noticeable in the eyes and on the palms of hands or soles of feet.

Along with jaundice, patients typically notice changes in their urine and stool. Dark urine, often described as tea-colored or cola-colored, occurs because excess bilirubin is excreted through the kidneys. Pale or clay-colored stools result from a lack of bile pigments reaching the intestines. These changes often appear before jaundice becomes visible and can be important early warning signs.

Abdominal discomfort is common during acute hepatitis B. Patients often describe a dull, aching pain or tenderness in the upper right portion of the abdomen, where the liver is located. This occurs because the inflamed liver swells and stretches its capsule. The discomfort may extend to the back or right shoulder and typically worsens after eating fatty foods.

Symptoms of Chronic Hepatitis B

Chronic hepatitis B is often called a "silent infection" because most people with chronic infection have no symptoms for years or even decades. The virus continues to replicate in the liver, causing slow but progressive damage, without causing noticeable symptoms. This is why chronic hepatitis B is often discovered incidentally during routine blood tests or when screening is performed for another reason.

When symptoms do occur in chronic hepatitis B, they are often vague and non-specific. Persistent fatigue is the most common complaint, affecting quality of life even when liver damage is minimal. Some patients experience intermittent right upper abdominal discomfort, especially during periods of viral reactivation or flares. These flares can occasionally cause symptoms similar to acute hepatitis.

How Does Hepatitis B Spread?

Hepatitis B spreads through contact with infected blood and body fluids. The main transmission routes are: unprotected sexual contact, sharing needles or syringes, mother-to-child transmission during childbirth, needlestick injuries in healthcare settings, and sharing personal items like razors or toothbrushes. Hepatitis B is NOT spread through casual contact, sharing food, coughing, or sneezing.

Understanding how hepatitis B is transmitted is essential for prevention. The hepatitis B virus is found in blood and other body fluids including semen, vaginal secretions, and saliva (though saliva contains lower concentrations). The virus is remarkably resilient and can survive outside the body on environmental surfaces for at least seven days, during which time it remains capable of causing infection if it enters an unvaccinated person's bloodstream.

Hepatitis B is 50-100 times more infectious than HIV, meaning that even a small amount of infected blood can transmit the virus. This high infectivity explains why transmission can occur through routes that might seem unlikely, such as sharing a toothbrush or razor with someone who is infected.

Sexual Transmission

Sexual contact is one of the most common routes of hepatitis B transmission in many parts of the world. The virus can be transmitted through vaginal, anal, and oral sex when there is contact with infected body fluids. Men who have sex with men (MSM) are at particularly high risk due to the mechanics of anal intercourse, which is more likely to cause small tears that allow the virus to enter the bloodstream. However, heterosexual transmission is also common and accounts for a significant proportion of new infections globally.

Using barrier protection (condoms or dental dams) significantly reduces, but does not eliminate, the risk of sexual transmission. The most effective protection is vaccination, which should be offered to all sexual partners of people with hepatitis B.

Blood-to-Blood Transmission

Direct contact with infected blood is an extremely efficient route of transmission. This includes:

• Injection drug use: Sharing needles, syringes, or drug preparation equipment is a major risk factor. Even microscopic amounts of blood left in equipment can transmit the virus.
• Healthcare exposures: Needlestick injuries or mucous membrane exposures to infected blood pose risks to healthcare workers. Proper use of personal protective equipment and post-exposure protocols are essential.
• Blood transfusions: While now rare in countries that screen blood donations, transmission through transfusion was historically significant and remains a risk in areas without proper screening.
• Tattooing and piercing: Equipment that is not properly sterilized can transmit the virus between clients.
• Sharing personal items: Razors, toothbrushes, nail clippers, and other items that may have trace amounts of blood can potentially transmit the virus.

Mother-to-Child Transmission (Perinatal Transmission)

Transmission from an infected mother to her baby during childbirth is one of the most important routes of hepatitis B spread globally, particularly in high-prevalence regions. Without intervention, the risk of transmission ranges from 70-90% when the mother has high viral load (is highly infectious). This is particularly concerning because infants infected at birth have a 90% chance of developing chronic infection, compared to only 5-10% for adults.

Fortunately, perinatal transmission is highly preventable. When infants born to hepatitis B-positive mothers receive both the hepatitis B vaccine and hepatitis B immune globulin (HBIG) within 12-24 hours of birth, followed by completion of the vaccine series, transmission is prevented in approximately 95% of cases. Pregnant women with very high viral loads may also receive antiviral treatment during the third trimester to further reduce transmission risk.

How Long Is Hepatitis B Contagious?

The infectious period for hepatitis B can be extensive. Infected individuals can transmit the virus starting approximately six weeks before any symptoms appear (if symptoms develop at all). In acute infection, a person remains contagious as long as the hepatitis B surface antigen (HBsAg) is detectable in their blood, which can be several months even after symptoms resolve.

People with chronic hepatitis B can potentially transmit the virus for their entire lives, though infectivity varies depending on viral load. Those with high viral loads (high HBV DNA levels) are most infectious. Importantly, treatment with antiviral medications can reduce viral load to undetectable levels, which significantly reduces (but may not completely eliminate) the risk of transmission.

Who Is at Risk for Hepatitis B?

Risk factors for hepatitis B include: being born to an infected mother, having unprotected sex with multiple partners or with someone who has HBV, injecting drugs, receiving frequent blood transfusions, being a healthcare worker, living with someone who has chronic HBV, traveling to high-prevalence regions, and having HIV or hepatitis C.

While anyone who is not immune can become infected with hepatitis B, certain groups face substantially higher risk. Understanding these risk factors helps identify people who should be prioritized for vaccination and screening. The WHO estimates that two-thirds of people living with chronic hepatitis B are unaware of their infection, highlighting the need for targeted testing programs.

High-Risk Groups for Hepatitis B

Healthcare guidelines worldwide recommend hepatitis B testing and vaccination for the following groups:

• People born in high-prevalence regions: This includes most of Asia, Africa, the Pacific Islands, parts of South America, and Eastern Europe, where chronic infection rates exceed 2%
• People who inject drugs: Current or past injection drug use is one of the strongest risk factors
• Men who have sex with men (MSM): Higher rates of infection due to sexual transmission patterns
• People with multiple sexual partners: Each new partner increases potential exposure
• Sexual partners of HBV-positive individuals: Direct exposure risk
• Household contacts of HBV-positive individuals: Risk from sharing personal items
• Healthcare workers: Occupational exposure to blood and body fluids
• Dialysis patients: Multiple exposures through medical procedures
• People living with HIV: Co-infection is common and more severe
• People with hepatitis C: Co-infection increases liver damage risk
• Inmates of correctional facilities: Higher prevalence in incarcerated populations
• Pregnant women: Universal screening prevents perinatal transmission

How Is Hepatitis B Diagnosed?

Hepatitis B is diagnosed through blood tests that detect viral proteins (antigens) and antibodies. The main tests are HBsAg (surface antigen - indicates current infection), anti-HBs (surface antibody - indicates immunity), anti-HBc (core antibody - indicates past or current infection), and HBV DNA (viral load - measures amount of virus). These tests can distinguish between acute infection, chronic infection, resolved infection, and vaccine-induced immunity.

Blood tests are the cornerstone of hepatitis B diagnosis. Unlike many infections where a single test can confirm or rule out disease, hepatitis B diagnosis requires a panel of tests to understand the full picture of a person's infection status and immune response. This is because the body produces different antibodies at different stages of infection, and the virus itself leaves distinct markers in the blood.

The hepatitis B panel typically includes three initial tests: hepatitis B surface antigen (HBsAg), hepatitis B surface antibody (anti-HBs), and hepatitis B core antibody (anti-HBc). The results of these tests, taken together, can reveal whether a person has never been infected, has current acute infection, has chronic infection, has recovered from past infection, or has vaccine-induced immunity.

Understanding Hepatitis B Blood Tests

Additional Tests for Chronic Hepatitis B

When chronic hepatitis B is diagnosed, additional tests are performed to assess the severity of infection and determine whether treatment is needed:

• HBV DNA (viral load): Measures the amount of virus in the blood. Higher levels indicate more active viral replication and greater liver damage risk.
• HBeAg and anti-HBe: These tests indicate the phase of chronic infection and help predict natural history.
• Liver function tests (ALT, AST): Elevated levels indicate liver inflammation and damage.
• FibroScan (transient elastography): Non-invasive ultrasound-based test that measures liver stiffness to assess fibrosis.
• Liver biopsy: Sometimes needed to assess the degree of liver damage and inflammation.
• AFP (alpha-fetoprotein): Tumor marker used for liver cancer surveillance.
• Hepatitis D co-infection testing: Recommended for all HBsAg-positive individuals.

How Is Hepatitis B Treated?

Acute hepatitis B usually resolves without specific treatment - most adults recover naturally with supportive care. Chronic hepatitis B cannot be cured but can be effectively managed with antiviral medications like entecavir or tenofovir, which suppress viral replication, reduce liver damage, and lower the risk of complications like cirrhosis and liver cancer.

The approach to treating hepatitis B depends entirely on whether the infection is acute or chronic, and for chronic infection, on the stage of disease and degree of liver damage. While there is no cure that completely eliminates the virus from the body, modern treatments can effectively control chronic infection and prevent its serious complications.

Treatment of Acute Hepatitis B

For most people with acute hepatitis B, no specific antiviral treatment is needed or recommended. The vast majority of healthy adults (90-95%) will naturally clear the virus within six months and develop lifelong immunity. During the acute phase, treatment focuses on supportive care:

• Rest: Adequate rest is important, though strict bed rest is not necessary
• Nutrition: Eating small, frequent meals can help with nausea; avoid fatty foods that may worsen symptoms
• Hydration: Drinking plenty of fluids is essential, especially if vomiting occurs
• Avoiding alcohol: Alcohol puts additional stress on the liver and should be avoided completely
• Avoiding hepatotoxic medications: Acetaminophen (paracetamol) and certain other drugs can stress the liver and should be used cautiously
• Symptom relief: Medications for itching (antihistamines) or nausea may be prescribed

In rare cases (less than 1%), acute hepatitis B can cause fulminant (sudden, severe) liver failure, which is a medical emergency requiring hospitalization and potentially liver transplantation. Patients with severe acute hepatitis B may receive antiviral treatment and should be closely monitored.

Treatment of Chronic Hepatitis B

Not everyone with chronic hepatitis B needs immediate treatment. The decision to start treatment depends on several factors including viral load, liver enzyme levels (ALT), degree of liver fibrosis, and overall health. Treatment is generally recommended for patients with:

• High viral load (HBV DNA > 2,000 IU/mL) with elevated liver enzymes
• Evidence of significant liver fibrosis or cirrhosis
• Family history of liver cancer or cirrhosis
• Certain conditions requiring immunosuppressive therapy
• Co-infection with HIV or hepatitis C or D

Two main types of medications are used to treat chronic hepatitis B:

Nucleos(t)ide Analogues (Oral Antivirals)

These are the most commonly used treatments and include entecavir (Baraclude) and tenofovir (Viread, Vemlidy). These medications work by interfering with the hepatitis B virus's ability to replicate. They are taken as daily pills and are highly effective at suppressing viral replication, with most patients achieving undetectable viral loads. Key points about these medications:

• Efficacy: Over 90% of patients achieve viral suppression
• Duration: Usually required long-term, often for life
• Side effects: Generally well-tolerated; rare kidney effects with some formulations
• Resistance: Entecavir and tenofovir have high barriers to resistance
• Pregnancy: Tenofovir is safe during pregnancy and can prevent mother-to-child transmission

Pegylated Interferon Alpha

Interferon-based treatment is an alternative approach that works by boosting the immune system's response to the virus. It is given as weekly injections for a defined period (usually 48 weeks). While it has the advantage of being a finite-duration treatment with a chance of achieving "functional cure," it has more side effects and is not suitable for everyone:

• Advantages: Finite duration; higher chance of HBsAg loss (functional cure)
• Disadvantages: Significant side effects (flu-like symptoms, fatigue, depression); not suitable for patients with decompensated cirrhosis
• Response rates: About 20-30% of patients achieve sustained response

How Can Hepatitis B Be Prevented?

Hepatitis B vaccination is the most effective way to prevent infection, providing over 95% protection. The vaccine is safe for all ages including newborns and pregnant women. Other prevention measures include using condoms during sex, not sharing needles or personal items like razors, and ensuring tattoo/piercing equipment is sterile. Post-exposure vaccination within 24 hours can prevent infection after exposure.

The hepatitis B vaccine is one of the most effective vaccines ever developed, with a complete series providing more than 95% protection against infection. It was the first vaccine capable of preventing a cancer (hepatocellular carcinoma) and has been described by the WHO as "the first anti-cancer vaccine." Since its introduction in 1982, over one billion doses have been administered worldwide, with an excellent safety record.

Hepatitis B Vaccination Schedule

The standard vaccination schedule for hepatitis B consists of three doses given over a six-month period. The first dose can be given at any time, the second dose is given at least one month after the first, and the third dose is given at least four months after the first dose (and at least two months after the second). Alternative accelerated schedules are available for certain situations.

Vaccination is recommended for:

• All infants: Starting within 24 hours of birth
• Children and adolescents: Who were not vaccinated as infants
• Healthcare workers: Due to occupational exposure risk
• People with multiple sexual partners: Or those with a history of sexually transmitted infections
• Men who have sex with men
• People who inject drugs
• Household and sexual contacts of HBV-positive individuals
• Patients on dialysis
• People with chronic liver disease
• People with HIV
• Travelers to regions with high HBV prevalence

Post-Exposure Prophylaxis

If an unvaccinated person is exposed to hepatitis B (for example, through a needlestick injury, sexual contact with an infected person, or being born to an infected mother), post-exposure prophylaxis (PEP) can prevent infection if given promptly. PEP typically includes:

• Hepatitis B vaccine: First dose given as soon as possible, preferably within 24 hours of exposure
• Hepatitis B immune globulin (HBIG): Provides immediate passive immunity; given along with the vaccine for high-risk exposures

The combination of HBIG and vaccine is 85-95% effective at preventing infection when given within 24 hours of exposure. Effectiveness decreases the longer the delay after exposure, and PEP is generally not effective if given more than 7 days after exposure (or 12-24 hours after birth for perinatal exposure).

Other Prevention Measures

• Safe sex practices: Use condoms consistently and correctly; limit number of sexual partners
• Never share needles: If injecting drugs, use sterile equipment every time
• Don't share personal items: Razors, toothbrushes, nail clippers, and other items that may have blood on them
• Choose reputable facilities: For tattoos, piercings, and other procedures involving needles
• Healthcare workers: Follow universal precautions; use protective equipment
• Pregnant women: Get tested; antiviral treatment and infant vaccination can prevent transmission

What Are the Complications of Hepatitis B?

Chronic hepatitis B can lead to serious complications including liver cirrhosis (scarring), liver failure, and hepatocellular carcinoma (liver cancer). These complications develop over years to decades of chronic infection. Regular monitoring and treatment can significantly reduce these risks. Cirrhosis develops in 15-25% of untreated chronic HBV patients.

The complications of hepatitis B are almost exclusively associated with chronic infection. Acute hepatitis B very rarely causes severe complications (less than 1% develop fulminant hepatic failure), and the vast majority of adults recover completely. However, chronic infection can silently damage the liver over many years, eventually leading to serious and potentially life-threatening conditions.

Liver Cirrhosis

Cirrhosis occurs when chronic inflammation causes progressive scarring (fibrosis) of the liver tissue. As more scar tissue forms, it replaces healthy liver cells and disrupts the liver's normal structure and function. Cirrhosis develops in approximately 15-25% of people with untreated chronic hepatitis B over a period of years to decades. Risk factors for progression to cirrhosis include:

• High viral load
• Prolonged infection (especially if acquired at birth)
• Alcohol consumption
• Co-infection with hepatitis C, D, or HIV
• Male sex
• Older age

Early-stage cirrhosis may cause no symptoms, but as it progresses, complications such as portal hypertension, ascites (fluid accumulation in the abdomen), variceal bleeding, and hepatic encephalopathy (confusion due to toxin buildup) can develop.

Hepatocellular Carcinoma (Liver Cancer)

Chronic hepatitis B significantly increases the risk of developing hepatocellular carcinoma (HCC), the most common type of primary liver cancer. HBV is responsible for approximately 50% of HCC cases worldwide. Unlike most cancers, HCC can develop in hepatitis B patients even without cirrhosis, although the risk is much higher in those who have developed cirrhosis.

The annual risk of HCC in people with chronic hepatitis B ranges from 0.5-1% in those without cirrhosis to 2-5% in those with cirrhosis. This is why regular surveillance with ultrasound and AFP testing every 6 months is recommended for high-risk patients. When detected early, HCC can often be successfully treated with surgery, ablation, or liver transplantation.

Hepatitis B and Pregnancy

All pregnant women should be tested for hepatitis B. If a mother has HBV, her baby can be protected through vaccination and hepatitis B immune globulin given within 12-24 hours of birth, which prevents transmission in about 95% of cases. Mothers with high viral loads may receive antiviral treatment during pregnancy to further reduce transmission risk.

Hepatitis B infection during pregnancy poses significant risks to the newborn. Without intervention, babies born to HBsAg-positive mothers have a 70-90% chance of becoming infected if the mother is also HBeAg-positive (indicating high viral load), and a 10-40% chance if HBeAg-negative. Because infants' immune systems are immature, 90% of those infected at birth will develop chronic hepatitis B, compared to only 5-10% of adults who become infected.

Fortunately, mother-to-child transmission is highly preventable with proper management:

• Universal prenatal screening: All pregnant women should be tested for HBsAg early in pregnancy
• Birth dose vaccination: The first dose of hepatitis B vaccine should be given within 12-24 hours of birth
• Hepatitis B immune globulin (HBIG): Given along with the vaccine for infants of HBsAg-positive mothers
• Completion of vaccine series: The remaining doses are given at 1-2 months and 6 months of age
• Antiviral treatment: Mothers with very high viral loads (>200,000 IU/mL) may receive tenofovir during the third trimester
• Post-vaccination testing: Infants born to HBsAg-positive mothers should be tested at 9-12 months of age

With these interventions, transmission can be prevented in approximately 95% of cases. Breastfeeding is safe and encouraged for mothers with hepatitis B, as long as the infant has received the birth dose vaccine and HBIG.