In the most general sense, hepatitis refers to inflammation and swelling of the liver. This problem is most often caused by a viral infection involving one of five viruses, but it can also occur in some people with autoimmune conditions, those on liver-damaging drugs, and people with excessive alcohol intake. Blood testing can detect the presence or absence of hepatitis-causing viruses, helping patients determine whether their liver problems are viral or caused by another factor. Hepatitis testing can also help determine whether a hepatitis vaccination program has been successful.

Hepatitis Symptoms
The symptoms of hepatitis are categorized as acute and chronic. Acute symptoms are those that occur in the short term. They include tiredness and malaise, aching joints and muscles, vomiting, nausea, intestinal problems and headache. Some people also suffer from a significant loss of appetite, dark urine and yellowed skin and eyes. The abdomen may hurt, smokers may no longer crave tobacco and some people have enlarged lymph nodes. In young people with viral hepatitis there may be no symptoms at all. In a small number of people, acute hepatitis turns into complete liver failure.

Chronic hepatitis is the condition of having liver inflammation over a long period of time. It is more difficult to diagnose than the acute type. Symptoms usually include weakness, tiredness and malaise. If jaundice, or yellowed skin, occurs, it is usually a sign of severe damage. Sufferers may bruise or bleed easily and may have swollen legs or abdomens, but they tend to lose weight overall. Abnormal menstruation, thyroid and kidney inflammation, acne and lung scarring may appear in women whose hepatitis was caused by an autoimmune problem.

Viral Hepatitis
Viral hepatitis is one of the most common forms. It can be caused by a number of unrelated viral infections, including Hepatitis A, Hepatitis B and Hepatitis C, as well as the less common Hepatitis D and Hepatitis E viruses. Some people with Herpes simplex, Epstein-Barr, yellow fever and cytomegalovirus also get hepatitis. Hepatitis A and B are the most common and can be vaccinated against. There is no hepatitis C vaccine, and this disease is the most common blood-borne one in the United States. Hepatitis D and E are related to Hepatitis A and B and are not common in the U.S.

Hepatitis Blood Tests
Different blood tests are required for each type of viral hepatitis. Most people from the U.S. only need to be concerned about Hepatitis A, B and C. The A virus is detected by checking for antibodies produced by the immune system. If a person has been exposed to Hepatitis A within 2 to 6 weeks of testing, their blood will be positive for antibodies. Many doctors recommend that people who intend to travel outside the country, especially to locations where hepatitis is common, receive vaccination before departing.

Hepatitis B cannot be detected by an antibody test, but it does show up on a surface antigen blood test. This disease is most likely to be spread through sharing needles, sexual contact or contaminated medical tools. About 2 billion people around the world have Hepatitis B. Hepatitis B blood tests can tell whether a patient currently has the disease and if that patient has previously had it and is now recovered. They can also be used to detect the presence of an effective vaccine.

Hepatitis C is spread primarily through the blood and can come from contact with contaminated blood at work, through shared needles, via unprotected sex, or through organ and blood donation from contaminated supplies. Most people get no symptoms of the disease, but they can have long-term liver problems. Hepatitis C infection also makes it more likely for a person to suffer from severe problems if they get Hepatitis A or B. The blood test used to diagnose this disease looks for antibodies in the bloodstream. About 150 to 200 million people around the world have this condition.

Hepatitis Vaccination
Vaccination is the best way to prevent Hepatitis A and B, while Hepatitis C is best prevented via safe sex and careful risk avoidance. Vaccination for Hepatitis A occurs in two separate doses. The first provides protection for up to 10 years, starting two to four weeks after the vaccine is administered. The second should be given six to 12 months later and can last for almost 30 years if administered correctly.

Hepatitis B vaccines can be administered to children within 12 hours of birth and will protect them for much of their lives. All vaccines come in three parts, administered over the course of about a year and a half. One to four months after all three vaccinations have been administered, a blood test is required to determine whether the patient is really protected against Hepatitis B. If a patient shows a low antibody response, he or she should be tested further to check for current or past infections, then re-vaccinated.