What is Hepatitis B?

Dr Lau Pik Onn / 08 May, 2020

Understanding Hepatitis BUnderstanding Hepatitis B

Hepatitis B is a serious form of liver infection caused by the Hepatitis B virus (HBV).

Hepatitis B can cause both acute (severe and sudden) and chronic (long-lasting) disease. It is a major global health problem, as chronic Hepatitis B infection places people at higher risk of developing liver cirrhosis and liver cancer.

Chronic Hepatitis B and C infection is the leading cause for liver cancer (60-70%).1 Hepatitis B carriers are also 100 times more likely to develop liver cancer (hepatocellular carcinoma) compared to non-Hepatitis B carriers.2 Liver cancer was the 4th most common cancer in men in Singapore from 2008 to 2012, according to the Singapore National Registry of Diseases Office.3

About 3.6% of population aged 18-79 in Singapore or 150,000 people are Hepatitis B carriers, but many are unaware of it.4 Hepatitis B infection often goes undiagnosed until a patient seeks help for advanced liver problems.

How is Hepatitis B spread?How is it spread?

The main mode of Hepatitis B transmission is through exposure to blood or bodily fluids of an infected person. The virus does not spread through sneezing, coughing or casual hugs.

You can get the virus from:

  • Unprotected sex with an infected person (through direct contact with bodily fluids such as blood, semen or vaginal secretions)
  • Sharing contaminated needles or syringes or improperly sterilised sharp instruments
  • Childbirth (passed from an infected mother to child)
  • Direct contact with open sores of an infected person
  • Blood transfusion, if blood was not properly screened for infection

You may be a Hepatitis B carrier and not show any symptoms. Being unaware, you may pass the virus to others.

What are the symptoms of Hepatitis B?Symptoms

Hepatitis B symptoms may range from mild to severe. Typical symptoms include:

  • Clay coloured stools

  • Dark coloured urine

  • Abdominal pain

  • Loss of appetite

  • Nausea

  • Fever and muscle aches

  • Prolonged fatigue

  • Jaundice (yellowing of skin and whites of eyes)

Who is at higher risk of Hepatitis B infection?Risk factors

You may be at an increased risk of Hepatitis B if you:

  • Frequently need blood or blood products (dialysis) and are regularly exposed to them (health care workers)
  • Share needles for recreational drugs
  • Have unprotected sex
  • Have a natural or acquired immune deficiency (HIV) or been diagnosed with cancer
  • Live with someone who has chronic HBV infection
  • Travel to regions with high infection rates of HBV (e.g. Asia, Pacific islands, Africa, Eastern Europe)

How is Hepatitis B diagnosed?Diagnosis

If you have any symptoms or have been exposed to Hepatitis B, your doctor will perform a physical examination and a blood test to detect signs of the virus in your body. Further tests may be carried out upon diagnosis.

Icon Health Screening tests for Hepatitis B in all of our screening packages to ensure you are at optimal health. To learn more about our comprehensive screening options, click here.

How to prevent Hepatitis B infection?How to prevent Hepatitis B infection?

Prevention is always better than cure. There are many things you may like to consider to prevent Hepatitis B infection, including getting vaccinated.

  • Get vaccinated – This involves three doses over six months. Singaporeans born before 1985 would not have been inoculated with Hepatitis B under the National Childhood Immunisation Programme, so it is important to talk about this with your doctor.
  • Avoid unprotected sex and casual sex with multiple sexual partners due to higher risk of Hepatitis B infection
  • Do not share needles, razors, toothbrushes or any sharp object that may break the skin
  • If receiving ear or body piercing, tattooing or acupuncture, make sure that disposable or sterilised instruments are used

How is Hepatitis B treated?Treatment

The majority of adults with acute Hepatitis B will usually clear the infection within six months without treatment. Treatment is mainly focused on managing symptoms. This involves bed rest and avoiding alcohol and TCM remedies, so as not to provide further stress on the liver.

If your immune system is unable to clear the Hepatitis B infection within six months, this can lead to chronic Hepatitis B. Chronic Hepatitis B increases your risk of developing liver cirrhosis (permanent liver scarring and shrinking), liver failure and liver cancer.

Your doctor may start you on antiviral medication to fight the disease before it progresses to liver cirrhosis.

What are the long-term side effects of Hepatitis B?Long-term side effects

Those who recover completely from Hepatitis B infection are immune. However, a small percentage of people become carriers (chronic HBV infection).

A carrier is someone who carries the virus permanently in their body but may not show any symptoms. This means they can spread the disease to others

They can also develop serious complications like

  • liver cirrhosis (permanent scarring and hardening of liver)
  • liver failure
  • liver cancer

Surveillance of patients with chronic Hepatitis B must be carried out regularly. How often you receive screening will depend on your risk profile. It is recommended that low-risk groups should have six-monthly blood tests and ultrasounds of the liver. Those in the edium and high-risk groups will be referred to a specialist.

Patients who have chronic Hepatitis B must:

  • Ensure that their sexual partner is vaccinated
  • Not share toothbrushes, razors, utensils or food
  • Not donate body parts
  • Cover open wounds

We expect the number of Hepatitis B carriers to decline over time with screening and immunisation.


For a full list of references, click here.
  1. Ringehan, M., McKeating, J. & Protzer, U. (2017). Viral hepatitis and liver cancer. Retrieved on 22 April 2020 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5597741/
  2. Arbuthnot, P. & Kew, M. (2001). Hepatitis B virus and hepatocellular carcinoma. Retrieved on 22 April 2020 from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2517704/
  3. National Registry of Diseases Office. (2015). Singapore Cancer Registry Annual Registry Report 2015. Retrieved on 22 April 2020 from https://www.nrdo.gov.sg/docs/librariesprovider3/Publications-Cancer/cancer-registry-annual-report-2015_web.pdf?sfvrsn=10
  4. (2016). ​​​​​​​​Hepatitis B: What You Need to Know. Retrieved on 22 April 2020 from https://www.healthxchange.sg/digestive-system/liver/hepatitis-b-need-know
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