Hepatitis A, B, C
- 1 Definition/Description
- 2 Prevalence
- 3 Characteristics/Clinical Presentation
- 4 Associated Co-morbidities
- 5 Aetiology/Causes
- 6 Systemic Involvement
- 7 Diagnostic Tests/Lab Tests/Lab Values
- 8 Management
- 9 Differential Diagnosis
- 10 Case Reports/ Case Studies
- 11 Resources
- 12 References
Hepatitis is defined as inflammation of the liver. This inflammation may be caused by various diseases, toxins, or viral infections.
Hepatitis A is a contagious liver infection caused by the hepatitis A virus. It causes inflammation that affects your liver's ability to function. It is the most common of the two hepatitis viruses enterically transmitted in the US and one of the two that is vaccine-preventable.
Hepatitis B is another contagious liver infection that is caused by the Hepatitis B virus. The virus can cause an acute, short-term, infection that may last for several weeks or months. The virus and infection may also lead to chronic infection, leading to a long-term illness.
Hepatitis C is an infection caused by a virus that attacks the liver and leads to inflammation. Most people who have the infection often do not know that they have the disease, and are often asymptomatic. It is considered to be among the most serious of the hepatitis viruses. About 80% of people who have the virus develop chronic hepatitis and many people also can develop cirrhosis or even liver cancer.
About 3,600 cases of Hepatitis A are reported each year. However, since not all people are symptomatic, more people are infected than are diagnosed and reported.
Estimates for the prevalence of the Hepatitis B virus claim that more than one-third of the world's population has been infected with 5% of the population being chronic carriers. Approximately 25% of all carriers will develop a serious liver disease, while there are over one million deaths due to the infection of the Hepatitis B virus. According to the CDC, there were an estimated 43,000 new Hepatitis B infections in the United States in 2007, with the number of acute infections significantly declining.  For chronic infections, estimates range from 800,000-1.4 million people in the United States.
Every year around 3-4 million people are infected with the Hepatitis C virus. About 150 million people are chronically infected and at risk of developing liver cirrhosis and even liver cancer. More than 350,000 people die from hepatitis C-related liver disease every year.
|Hepatitis A||Hepatitis B||Hepatitis C|
Symptoms usually do not appear until 2-6 weeks after you have been exposed to the virus. They are usually mild, but can last up to several months (2-6 months), especially in adults
It is important to note that not everyone will develop signs and symptoms of the virus.
Acute infections may present with no symptoms, present with a gradual onset of symptoms in a few days-weeks, or present with symptoms very quickly. Adults and children older than 5 are most likely to show symptoms of an acute Hepatitis B infection typically within 90 days of the exposure, but may show between 6 weeks and 6 months of the exposure to the virus. Acute symptoms may last several weeks or up to 6 months.
Chronic Hepatitis B infection may result in ongoing symptoms or may be symptom free for as many as 30 years.
Early on, Hepatitis C usually is asymptomatic. When signs and symptoms begin to set in, they are generally mild and flu-like.
About 75-85% of recently infected people develop chronic disease and 60-70% of chronically infected people develop chronic liver disease. Also 5-20% develop cirrhosis and 1-5% die from cirrhosis or liver cancer.
| 1. Dark urine
4. Loss of appetite
5. Low-grade fever
6. Nausea and vomiting
7. Pale or clay-colored stools
9. Abdominal pain
12. Muscle Pain
3. Loss of appetite
3. Nausea and vomiting
4. Abdominal Pain
5. Dark urine
6. Clay-colored bowel movements
7. Muscle and joint pain
9. Symptoms of liver damage for chronic infections
| 1. Fatigue|
3. Nausea or poor appetite
4. Muscle and joint pains
5. Tenderness of your liver
6. Abdominal pain
7. Dark urine
8. Grey-coloured faeces
10. Abdominal swelling
Some co-morbidities that may be associated with Hepatitis A, B, C include:
- Maladaptive lifestyle habits
- Poor quality of life
- Liver disease
- Disorders of lipid metabolism
- Non-traumatic joint disorders
- GI disorders
- Blood-clotting disorders
||Hepatitis A||Hepatitis B||Hepatitis C|
|Cause||Hepatitis A virus||Hepatitis B virus||Hepatitis C virus|
Method of transmission
Mostly found in stools and blood of infection person and is therefore spread primarily via person-to-person contact.
Hepatitis A can spread when a person unknowingly ingests the virus from objects, food, or drinks contaminated by small, undetected amounts of stool from an infected person. (CDC)
Hepatitis A can also spread from close personal contact with an infected person such as through sex or caring for someone who is ill.
|Spread through contact with body fluids such as semen, vaginal fluids, saliva, and blood.||Spread when come into contact with contaminated blood.|
|Contracted when exposed to:||
1. Food or drink that has been contaminated by stools containing the Hepatitis A virus
2. Contact with stool or blood of a person infected
3. A person with the disease does not wash his/her hands properly after using the restroom and touches other objects or foods
4. Participating in sexual practices involving oral-anal contact with an infected individual
1. Childbirth- passed from mother to child
2. Sexual contact from unprotected intercourse
3. Shared needles- injection drug use or those given contaminated with syringes an needle-stick injuries in healthcare settings
4. Sharing personal items such as razors or toothbrushes with an indivdual infected
5. Direct contact with blood or an open sore of an individual infected
6. Any blood or bodily fluid touches skin, eyes, or mouth
1. Blood transfusions and organ transplants before 1992.
2. Shared needles- injection drug use or those given with contaminated syringes and needle-stick injuries in health-care settings
3. Childbirth- passed from mother to child
4. Sexual contact from unprotected intercourse
5. Long-term kidney dialysis
6. Regular contact with blood work
7. Sharing personal items such as razors or toothbrushes with an individual infected
2. Native people of America
3. Restaurant workers and food handlers
4. Children living in communities that have high rates of the disease
5. Children and workers in day care facilities
6. Individuals engaging in anal/oral sex with STDs or HIV
7. People with chronic liver disease
8. If you eat raw shellfish frequently
9. Laboratory workers who handle live Hepatitis
1. Unprotected sexual intercourse with an infected partner
2. Blood transfusions (uncommon in the United States)
3. Contact with blood at work
4. Long-term kidney dialysis
5. Receiving a tattoo or acupuncture with an unclean needle
6. Sharing needles during drug use
7. Sharing personal items with an infected individual
9. Travelling to countries with high rates of the virus
10. Men who have sexual contact with other men
11. Living with a person infected with chronic Hepatitis B
Variable systemic involvement can occur with Hepatitis due to the nature of the virus causing a widespread infection in the body. Most predominantly the infection involves the liver and lymphatic system. Other systemic areas of involvement include progression into renal, endocrine, dermatological, cardiovascular, rheumatologic, and central nervous system diseases.
Diagnostic Tests/Lab Tests/Lab Values
A primary care physician will conduct a physical exam when looking for Hepatitis A Virus. During the physical exam, they may find that you have an enlarged and tender liver. Also, they will have you partake in blood tests. The blood tests will look at IgM and IgG antibody levels as well as liver enzymes. In both cases, the antibody and enzyme levels will be raised.
Blood tests are done to check for the Hepatitis B virus. The blood tests available may include:
|Hepatitis B Surface Antigen||HBsAG||Positive test means the person has an acute or chronic infection and can transmit the virus to others.|
|Hepatitis B Surface Antibody||anti-HBs||Positive test means a person is immune from getting the virus.|
|Total Hepatitis B Core Antibody||anti-HBc||Positive test means a person is currently or previously has been infected.|
|IgM Antibody to Hepatitis B Core Antigen||IgM anti-HBc||Positive test means a person has been infected within the past 6 months.|
|Hepatitis B "e" Antigen||HBeAg||Positive test means a person has high levels of the virus in the blood and can spread the virus to others easily.|
|Hepatitis B e Antibody||HBeAb or anti-HBe||Positive test means a person has a chronic infection but have low levels of the virus in their blood.|
|Hepatitis B Viral DNA||Positive test means the virus is multiplying and is highly contagious or the person has a chronic infection with an increased risk for liver damage.|
Blood tests are also done to check for the Hepatitis C Virus. They specifically look at EIA assay to detect the hepatitis C antibody and the hepatitis C RNA assay to measure virus levels. Genetic testing can be done to check for the hepatitis C genotype. Six different genotypes exist. Most people have genotype 1 infection, which is the hardest to treat. Genotypes 2 and 3 are also common, but typically respond better to treatment. Tests can also be done to monitor the amount of liver damage: albumin levels, liver function tests, and prothrombin time. A liver biopsy can also be done to assess liver damage.
There is no specific treatment for Hepatitis A. Rest is recommended when the symptoms are most severe. Individuals with acute hepatitis should avoid alcohol and any substances that are toxic to the liver, such as Tylenol. Fatty foods that can cause vomiting should also be avoided during the acute phase. It is important to maintain comfort and an adequate nutritional balance as recovery can take several weeks up to a month. It is also important to constantly replace fluids that you may be losing. It is most important to prevent contracting the disease. Sexual activities should be avoided with an individual who has Hepatitis A, as a condom does not offer adequate protection. Also, wash your hands thoroughly after using the toilet, whether a person is infected or not. Refrain from preparing food for others while one is infected, as this way the disease is passed on. Also avoid unclean food or water, especially if travelling.
There is no available treatment for acute Hepatitis B infections. Patients with acute infection are recommended to rest and get an adequate nutritionally intake of food and fluids.
Individuals with chronic Hepatitis B medical management will involve medical monitoring, abstinence from alcohol, and antiviral therapy in order to suppress the infection and end the active liver disease. These individuals should avoid consumption of alcohol completely because it makes the liver disease worse. Antiviral therapy is appropriate for patients with a chronic Hepatitis B infection who have tested positive for hepatitis B surface antigen for at least six months, have abnormal blood levels of liver enzymes, actively dividing virus in the blood, and a liver biopsy showing moderate disease activity. Antiviral therapy helps in preventing further liver damage. Approved drugs for Hepatitis B include:
|Method||Adverse Side Effects|
Multiple times per week for 6 months-1 year
|flu-like symptoms, depression, headaches|
used with high levels of the virus to stimulate the immune system
Once weekly for 6 months-1 year
|flu-like symptoms, depression, various persistent unpleasant side effects|
prevent the virus from spreading by preventing the genetic code from being copied
Once-daily for at least 1 year
|diarrhoea, nausea, skin rash, feeling of weakness, dizziness|
|Entecavir||nausea, insomnia, dizziness|
|few side effects but not recommended as first line of treatment due to high rate of viral resistance|
Hepatitis C does not always require treatment. There are 6 genotypes of Hepatitis C and they all respond differently to a treatment. A good screening is required before starting the treatment to determine the most appropriate approach. Combination of antiviral therapy with interferon and ribavirin has been the most common form of treatment for Hepatitis C. Interferon is not widely available globally and is not well tolerated depending on the genotype the patient presents with. Therefore, not all patients finish their interferon treatment. Two new drugs have been developed that may be better tolerated and they are telaprevir and boceprevir. However, more testing needs to be done to ensure that these new drugs lead to greater access and treatment globally. Since the Hepatitis C virus infects the blood and can lead to cirrhosis of the liver or liver cancer, the goal of medication is to prevent this from happening. Many patients with hepatitis C benefit from treatment with medications similar to Hepatitis B. The most common medication include antiviral medications including pegylated interferon alfa and ribavirin. Typically pegylated interferon alfa is received weekly through injections. Ribavirin is a capsule taken twice daily. Treatments are given from 24-48 weeks. Two newer drugs that may be available for use for patients with genotype 1 are Telaprevir and Boceprevir. These medications do have several side effects, and therefore, patients need to be watched closely. Some of the side effects of the medications can include depression and flu-like symptoms.
If the liver has been severely damaged, a liver transplant may be an option. It is important to realize that a liver transplant is not the cure and the use of antiviral medications continues after the liver transplant takes place.  It is also recommended that people be careful not to take vitamins, nutritional supplements, or new over-the-counter medications without first discussing it with their primary care physician. It is important to avoid any substances that are toxic to the liver such as alcohol, as it can speed up the progression of the disease.
With all three of the diseases preventing contraction of the virus, and therefore the infection is key. Prevention can help avoid passing on the disease or contracting the illness. The risk of infection can be reduced by:
- Receiving Hepatitis A and B vaccines
- Avoiding unnecessary and unsafe injections
- Avoiding unsafe blood products
- Avoiding unsafe sharps and waste collection and disposal
- Avoiding the use of illicit drugs and sharing injection equipment
- Avoiding unprotected sex with infected individuals
- Avoiding the sharing of sharp personal items that may be contaminated with infected blood
- Avoiding tattoos, piercings, and acupuncture performed with contaminated equipment
If you have been exposed to the Hepatitis A infection and have not had it before or have not received the vaccine, ask your doctor or nurse about receiving either immune globulin or the Hepatitis A vaccine. Vaccines that protect against the virus are available and begin to protect you for weeks after receiving the initial dose. The 6-12 month booster is required for long-term protection. It is especially important that children age 12-23 months or adults at high risk for contracting the virus get a vaccine. Also it is important for anyone one year of age and older traveling to or working in countries with high or intermediate prevalence of Hepatitis A (central or south America, Mexico, Asia), children and adolescents 2-18 who live in states or communities where routine vaccination has been implanted because of high disease prevalence, men who have sex with men, people who use street drugs, people with chronic liver disease, people who are treated with clotting factors, and people who work in HAV laboratories to get vaccinated for safety reasons.
Hepatitis B can be prevented in 95% of recipients with the proper vaccine. Individuals who believe they may have contracted the Hepatitis B virus can receive the Hepatitis B vaccine, the Hepatitis B immune globulin, within 24 hours to potentially prevent infection. A surface antigen of the Hepatitis B virus is what makes up the vaccine. These vaccines are produced by two methods: plasma-derived or recombinant DNA.
All individuals suffering from chronic liver diseases, such as Hepatitis B and C, should receive Hepatitis A immunization as well as the Hepatitis B immunization.
Physical Therapy Management
A multifaceted approach is needed in the treatment of Hepatitis A, B, and C. No specific physical therapy intervention is appropriate for the specific infection of Hepatitis, but Hepatitis may likely be a comorbidity of a patient seen in physical therapy. With any other medical condition, it is important to educate patients on their disease and risk factors to promote awareness and improvement in their healthy lifestyle. In physical therapy, an emphasis on proper musculoskeletal health will be an important foundation for the patient's overall health. Stretching to improve flexibility could help alleviate symptoms of muscle pain. It is also important for the patient to remain physically active in order to maintain the healthiest lifestyle possible and prevent the patient from developing secondary co-morbidities due to inactivity. General strengthening and aerobic activity might be appropriate for a deconditioned patient. Individualizing a physical therapy program focusing on the impairments of the patient is of utmost importance for any patient.
During physical activity, it is important to monitor the patient for signs and symptoms of fatigue. For Hepatitis A bed rest is the recommended form of treatment and being aware of the acuteness of the Hepatitis infection is important when screening for physical therapy. Supportive therapy and patient education are used to ensure the patient is comfortable and has an adequate nutritional balance for all three infections. It is also important to remind the patient to refrain from the use of alcohol or intake of fatty substances.
Differential diagnosis for acute Hepatitis includes:
- Epstein-Barr Virus: leads to infectious mononucleosis with presenting symptoms of fever, sore throat, swollen lymph glands, swollen liver or spleen, jaundice, right upper quadrant pain
- Cytomegalovirus: usually affecting infants where the symptoms of the infection vary
- Alcoholic Hepatitis: jaundice, scleral icterus, muscle wasting, ascites, oedema, spider angiomata, asterixis,
- Drug-Induced Liver Injury
- Mushroom Ingestion: stomachaches, drowsiness, confusion, gastrointestinal issues, heart, liver or kidney damage
- "Shock Liver:" low cardiac output leading to hepatic ischemia presenting with low blood pressure to cause weakness and lightheadedness and liver damage
Differential diagnosis for chronic Hepatitis includes:
- Non-alcoholic steatohepatitis: diagnosed by excluding other causes and the presence of a fatty liver because there are few symptoms of the disease that could possibly include fatigue, weight loss, weakness, cirrhosis in late stages
- Chronic Alcoholic Hepatitis: pain and swelling in abdomen, decreased appetite and weight loss, nausea and vomiting, fatigue, dry mouth, increased thirst, bleeding of the esophagus, jaundice, spider-like veins, dry or pale skin, redness of feet/hands, itching, cognitive issues, fainting, numbness in legs and feet
- Primary Biliary Cirrhosis: inflamed and damaged bile ducts presenting with fatigue, pruritus, dry eyes/mouth, jaundice
- Primary Sclerosing Cholangitis: swelling and scarring of bile ducts presenting with fatigue, itching, jaundice, enlarged liver or spleen, weight loss, repeat cholangitis
- Hereditary Hemochromatosis: genetically inherited iron overload disease presenting with joint pain, fatigue, abdominal pain, loss of sex drive, cardiovascular issues
- Wilson's Disease: genetically inherited disease of copper overload presenting with swelling of the liver or spleen, jaundice, fluid buildup in the legs/abdomen, easily bruised, fatigue, physical coordination, tremors, muscle stiffness, behavioral changes, anemia, low platelet count, low WBC count, slower clotting time
- Alpha-1-antitrypsin deficiency: genetically inherited disease that presents as lung disease but can be associated with liver disease and cirrhosis of the liver
- Celiac Disease: condition that damages the lining of the small intestine to prevent absorption of parts of food that presents with abdominal pain, constipation, decreased appetite, lactose intolerance, diarrhoea, nausea and vomiting, unexplained weight loss, stools that float or are foul-smelling, bruising easily, depression, fatigue, delay of growth, hair loss, itchy skin, missed menstrual periods, mouth ulcers, muscle cramps, joint pain, nosebleeds, seizures, tingling/numbness in hands/feet
- Primary liver cancer
- Metastatic cancer
- Herpes Simplex Virus: visceral involvement in infants and pregnant women specifically the oesophagus, lungs, and liver with HSV viremia
- Varicella-Zoster Virus: generalized rash is typical but can also present with encephalitis, pneumonitis, myocarditis, and hepatitis
- Human Parvovirus: can present with haematological disorders that may present similar to hepatitis
Alternate diagnosis for Hepatitis A
Some alternate diagnoses for Hepatitis A that could be made based on the presenting signs and symptoms could be:
- Budd-Chiari Syndrome: uncommon condition induced by thrombotic or non-thrombotic obstruction to hepatic venous outflow. Hepatomegaly, ascites, and abdominal pain are characteristics of the disorder
- Cytomegalovirus: resulting in fever of unknown origin, pneumonia, hepatitis, encephalitis, myelitis, colitis, uveitis, retinitis, and neuropathy
- Other Hepatitis Virus
Differential diagnosis for Hepatitis B include:
- Alcoholic liver disease
- Non-alcoholic fatty liver disease
- Autoimmune hepatitis
- Metabolic and genetic disorders
- Drug-induced liver disease
- Granulomatous disorders
Differential diagnosis for Hepatitis C are:
- Alcohol Liver Disease: Complications such as oesophageal or gastric variceal bleeding, ascites, coagulopathy, hepatic encephalopathy, and liver cancer are associated with the disease.
- Hepatic Steatosis: Non-alcoholic hepatic steatosis, or non-alcoholic fatty liver disease, is the most common cause of chronic liver disease.
- Hemochromatosis: An autosomal-recessive disorder of inappropriately increased dietary iron absorption and increased iron release from erythrophagocytosis; Presenting features include fatigue, arthralgias, and diabetes mellitus
- Other Chronic Liver Dieases
- Autoimmune Hepatitis: Autoimmune hepatitis is a chronic disease of unknown cause, characterized by continuing hepatocellular inflammation and necrosis and tending to progress to cirrhosis.
- Cholangitis: an infection of the biliary tract with the potential to cause significant morbidity and mortality.
- Viral Hepatitis
Case Reports/ Case Studies
ResourcesHepatitis C Virus Advocate
- Centers for Disease Control and Prevention. Information for the Public: Hepatitis B FAQs. http://www.cdc.gov/hepatitis/b/bFAQ.htm#statistics (accessed March 3, 2013).
- Mayo Clinic. Hepatitis A. http://www.mayoclinic.com/health/hepatitis-a/DS00397 (accessed February 19, 2013)
- Hepatitis Foundation International. Hepatitis A (HAV). http://www.hepatitisfoundation.org/HEPATITIS/Hepatitis-A.html (accessed February 19, 2013)
- Mayo Clinic. Hepatitis C. http://www.mayoclinic.com/health/hepatitis-c/DS00097 (accessed February 19, 2013)
- Hepatitis Foundation International. Hepatitis C (HCV). http://www.hepatitisfoundation.org/HEPATITIS/Hepatitis-C.html (accessed February 19, 2013)
- PubMed Health. Hepatitis A. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001323/ (accessed February 19, 2013)
- World Health Organization, Global Alert and Response (GAR). Hepatitis B. http://www.who.int/csr/disease/hepatitis/whocdscsrlyo20022/en/index4.html (accessed March 3 2013).
- World Health Organization. Hepatitis C. http://www.who.int/mediacentre/factsheets/fs164/en/ (accessed February 19,2013)
- PubMed Health: A.D.A.M. Encyclopedia. Hepatitis B. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001324/ (accessed March 3, 2013).
- PubMed Health. Hepatitis C. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001329/ (accessed February 19, 2013)
- Basseri B, Yamini D,Chee G, and et al. Comorbidities associated with the increasing burden of hepatitis C infection. Liver International. Volume 30, Issue 7, pages 1012–1018, August 2010. Article first published online: 8 APR 2010fckLRDOI: 10.1111/j.1478-3231.2010.02235.x. http://onlinelibrary.wiley.com/doi/10.1111/j.1478-3231.2010.02235.x/abstract (accessed February 19, 2013)
- Louie K, Laurent S, Forssen U, & et al. The high comorbidity burden of the hepatitis C virus infected population in the United States. BMC Infectious Diseases 2012, 12:86 doi:10.1186/1471-2334-12-86. http://www.biomedcentral.com/1471-2334/12/86 (accessed February 19, 2013)
- Patel D, Shah P. A case report on comorbidities and laboratory abnormalities of Telbivudine in Hepatitis B Patients. Jaipur-302025. http://www.pharmatutor.org/articles/report-on-comorbidities-and-laboratory-abnormalities-of-telbivudine-in-hepatitis-b (accessed March 4, 2013).
- Zignego AL, Gragnani L, Giannini C, Laffi G. The Hepatitis C Virus Infection as a Systemic Disease.Intern Emerg Med 2012;7(Suppl 3):S201-S208.
- World Health Organization. Hepatitis A. http://www.who.int/mediacentre/factsheets/fs328/en/ (accessed February 19, 2013)
- Center for Disease Control. Medical Management of Chronic Hepatitis B and Chronic Hepatitis C. http://www.cdc.gov/idu/hepatitis/manage_chronich_hep_b-c.pdf (accessed March 2, 2013).
- NHS Choices. Hepatitis B-Treatment. http://www.nhs.uk/Conditions/Hepatitis-B/Pages/Treatment.aspx (accessed March 10, 2013).
- Hepatitis B Foundation. Approved Drugs for Adults. http://www.hepb.org/patients/hepatitis_b_treatment.htm. (accessed March 2, 2013).
- Kukka CM. Hepatitis B Fact Sheet: A series of fact sheets written by experts in the field of liver disease Which Hepatitis B Drug Treatment to Use First. Hepatitis C Support Project, February 2012.
- Center for Disease Control. Hepatitis A Vaccine. http://www.cdc.gov/vaccines/pubs/vis/downloads/vis-hep-a.pdf (accessed February 19, 2013)
- Differential Diagnosis of Elevated Liver Tests. http://members.aapa.org/aapaconf2006/syllabus/6206MoonAbnormalLiverFunction.pdf (accessed March 3, 2013).
- X-Plain. Epstein-Barr Virus/Mono Reference Summary. http://www.nlm.nih.gov/medlineplus/tutorials/epsteinbarrvirusmono/id299104.pdf (accessed March 3, 2013)
- Gallegos-Orozco JF, Rakela-Brodner J. Hepatitis Viruses: Not Always What it Seems to Be. Rev Med Chile 2010; 138:1302-1311
- Kid's Health. Cytomegalovirus. http://kidshealth.org/parent/infections/bacterial_viral/cytomegalovirus.html (accessed March 3, 2013).
- Children's Hospital of Philadelphia. The Poison Control Center- Mushrooms. http://www.chop.edu/service/poison-control-center/resources-for-families/mushrooms.html (accessed March 13, 2013).
- PubMedHealth. A.D.A.M. Medical Encyclopedia- Hepatic Ischemia. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001262/ (accessed March 3, 2013).
- U.S. Department of Health and Human Services. National Digestive Diseases Information Clearinghouse- Nonalcoholic Steatohepatitis. http://www.digestive.niddk.nih.gov/ddiseases/pubs/nash/#symptoms (accessed March 3, 2013).
- MedlinePlus. Alcoholic liver disease. http://www.nlm.nih.gov/medlineplus/ency/article/000281.htm (accessed March 3, 2013).
- U.S. Department of Health and Human Services. National Digestive Disease Information Clearinghouse- Primary Biliary Cirrhosis. http://digestive.niddk.nih.gov/ddiseases/pubs/primarybiliarycirrhosis/index.aspx (accessed March 3, 2013).
- PubMed Health. A.D.A.M Medical Encyclopedia- Sclerosing Cholangitis. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001330/ (accessed March 3, 2013).
- Gene Gateway-Exploring Genes and Genetic Disorders. Genetic Disorder Profile: Hemochromatosis. http://www.ornl.gov/sci/techresources/Human_Genome/posters/chromosome/hh.shtml (accessed March 3, 2013).
- U.S. Department of Health and Human Services. National Digestive Disease Information Clearinghouse- Wilson Disease. http://digestive.niddk.nih.gov/ddiseases/pubs/wilson/ (accessed March 3, 2013).
- National Human Genome Research Institute. Learning About Alpha-1 Antitrypsin Deficiency (AATD). http://www.genome.gov/19518992 (accessed March 3, 2013).
- PubMed Health. A.D.A.M Medical Encyclopedia- Celiac Disease-Sprue. http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001280/ (accessed March 3, 2013).
- Medscape Reference. Budd-Chiari Syndrome. http://emedicine.medscape.com/article/184430-overview (accessed February 19, 2013)
- Medscape Reference. Cytomegalovirus. http://emedicine.medscape.com/article/215702-overview (accessed February 19, 2013)
- Medscape Reference. Viral Hepatitis. http://emedicine.medscape.com/article/775507-overview (accessed February 19, 2013)
- Clinical Knowledge Summaries. Hepatitis B Management. http://www.cks.nhs.uk/hepatitis_b/management/scenario_diagnosis/differential_diagnosis (accessed March 3, 2013).
- British Medical Journal. Alcohol Liver Disease. http://bestpractice.bmj.com/best-practice/monograph/1116.html (accessed February 19, 2013)
- British Medical Journal. Hepatic Steatosis. http://bestpractice.bmj.com/best-practice/monograph/796.html (accessed February 19, 2013)
- British Medical Journal. Haemochromatosis. http://bestpractice.bmj.com/best-practice/monograph/134.html (accessed February 19, 2013)
- British Medical Journal. Assessment of Liver Dysfunction. http://bestpractice.bmj.com/best-practice/monograph/1122.html (accessed February 19, 2013)
- Medscape Reference. Autoimmune Hepatitis. http://emedicine.medscape.com/article/172356-overview (accessed February 19, 2013)
- Medscape Reference. Cholangitis. http://emedicine.medscape.com/article/184043-overview (accessed February 19, 2013)
- Medscape Reference. Hepatitis C Differential Diagnoses. http://emedicine.medscape.com/article/177792-differential (accessed February 19, 2013)