What is encephalitis?
Encephalitis is inflammation (swelling) of the brain. It can happen when an infection or medical condition that affects the brain activates your immune system. The inflammation can cause a wide range of symptoms. In extreme cases, it can lead to brain damage, stroke, or even death.
What causes encephalitis?There are different types of encephalitis, based on what the cause is. The two main types are infectious encephalitis and autoimmune encephalitis.
Infectious encephalitis is usually caused by a virus. In fact, viruses are the most common cause of encephalitis. Some of the different viruses that cause it include:
Bacteria, fungi, and parasites can also cause infectious encephalitis. But this is not common.
Autoimmune encephalitis happens when your immune system mistakenly attacks healthy brain cells. It can be triggered by conditions such as certain cancers, benign tumors, and infections. Sometimes the cause is not known.
Who is more likely to get encephalitis?Anyone can get encephalitis, but you are more likely to get it if you:
The symptoms of encephalitis can vary a lot, depending on how severe it is. Many people do not have any symptoms. Others may have mild flu-like symptoms such as fever, fatigue, headache, or body aches. If encephalitis becomes more serious, it can cause:
Encephalitis can be dangerous in infants. Their symptoms may include:
If you or your child is having symptoms of encephalitis, it's important to get medical care right away.
How is encephalitis diagnosed?To find out if you have encephalitis, your health care provider:
Most people with encephalitis will need treatment in the hospital. Depending on the cause, treatments may include antiviral medicines, antibiotics, corticosteroids, and other medicines.
For some types of encephalitis, there is no medicine to treat it. But rest, nutrition, and fluids can help your body fight the infection and relieve symptoms.
Some people may need physical, speech, and occupational therapy once the illness is under control.
Can encephalitis be prevented?There are steps you can take to help prevent encephalitis that is caused by infections:
NIH: National Institute of Neurological Disorders and Stroke
What is fatty liver disease?
Your liver is the largest organ inside your body. It helps your body digest food, store energy, and remove poisons. Fatty liver disease is a condition in which fat builds up in your liver. There are two main types:
NAFLD is a type of fatty liver disease that is not related to heavy alcohol use. There are two kinds:
Alcoholic fatty liver disease is due to heavy alcohol use. Your liver breaks down most of the alcohol you drink, so it can be removed from your body. But the process of breaking it down can generate harmful substances. These substances can damage liver cells, promote inflammation, and weaken your body's natural defenses. The more alcohol that you drink, the more you damage your liver. Alcoholic fatty liver disease is the earliest stage of alcohol-related liver disease. The next stages are alcoholic hepatitis and cirrhosis.
Who is at risk for fatty liver disease?The cause of nonalcoholic fatty liver disease (NAFLD) is unknown. Researchers do know that it is more common in people who:
NAFLD affects about 25% of people in the world. As the rates of obesity, type 2 diabetes, and high cholesterol are rising in the United States, so is the rate of NAFLD. NAFLD is the most common chronic liver disorder in the United States.
Alcoholic fatty liver disease only happens in people who are heavy drinkers, especially those who have been drinking for a long period of time. The risk is higher for heavy drinkers who are women, have obesity, or have certain genetic mutations.
What are the symptoms of fatty liver disease?Both NAFLD and alcoholic fatty liver disease are usually silent diseases with few or no symptoms. If you do have symptoms, you may feel tired or have discomfort in the upper right side of your abdomen.
How is fatty liver disease diagnosed?Because there are often no symptoms, it is not easy to find fatty liver disease. Your doctor may suspect that you have it if you get abnormal results on liver tests that you had for other reasons. To make a diagnosis, your doctor will use:
As part of the medical history, your doctor will ask about your alcohol use, to find out whether fat in your liver is a sign of alcoholic fatty liver disease or nonalcoholic fatty liver (NAFLD). He or she will also ask which medicines you take, to try to determine whether a medicine is causing your NAFLD.
During the physical exam, your doctor will examine your body and check your weight and height. Your doctor will look for signs of fatty liver disease, such as:
You will likely have blood tests, including liver function tests and blood count tests. In some cases you may also have imaging tests, like those that check for fat in the liver and the stiffness of your liver. Liver stiffness can mean fibrosis, which is scarring of the liver. In some cases you may also need a liver biopsy to confirm the diagnosis, and to check how bad the liver damage is.
What are the treatments for fatty liver disease?Doctors recommend weight loss for nonalcoholic fatty liver. Weight loss can reduce fat in the liver, inflammation, and fibrosis. If your doctor thinks that a certain medicine is the cause of your NAFLD, you should stop taking that medicine. But check with your doctor before stopping the medicine. You may need to get off the medicine gradually, and you might need to switch to another medicine instead.
There are no medicines that have been approved to treat NAFLD. Studies are investigating whether a certain diabetes medicine or Vitamin E can help, but more studies are needed.
The most important part of treating alcohol-related fatty liver disease is to stop drinking alcohol. If you need help doing that, you may want to see a therapist or participate in an alcohol recovery program. There are also medicines that can help, either by reducing your cravings or making you feel sick if you drink alcohol.
Both alcoholic fatty liver disease and one type of nonalcoholic fatty liver disease (nonalcoholic steatohepatitis) can lead to cirrhosis. Doctors can treat the health problems caused by cirrhosis with medicines, operations, and other medical procedures. If the cirrhosis leads to liver failure, you may need a liver transplant.
What are some lifestyle changes that can help with fatty liver disease?If you have any of the types of fatty liver disease, there are some lifestyle changes that can help:
Giant cell arteritis is a disorder that causes inflammation of your arteries, usually in the scalp, neck, and arms. It narrows the arteries, which keeps blood from flowing well. Giant cell arteritis often occurs with another disorder called polymyalgia rheumatica. Both are more common in women than in men. They almost always affect people over the age of 50.
Early symptoms of giant cell arteritis resemble the flu: fatigue, loss of appetite, and fever. Other symptoms include:
Your doctor will make the diagnosis based on your medical history, symptoms, and a physical exam. There is no specific test for giant cell arteritis, but you may have tests that measure inflammation.
Treatment is usually with corticosteroids. Early treatment is important; otherwise there is a risk of permanent vision loss or stroke. However, when properly treated, giant cell arteritis rarely comes back.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
What is HIV?
HIV stands for human immunodeficiency virus. HIV harms your immune system by destroying a type of white blood cell that helps your body fight infection. This puts you at risk for other infections and diseases.
What is AIDS?AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. It happens when the body's immune system is badly damaged because of the virus. Not everyone with HIV develops AIDS.
How does HIV spread?HIV is spread through certain body fluids from a person who has HIV. This can happen:
Anyone can get HIV, but certain groups have a higher risk of getting it:
Factors such as stigma, discrimination, income, education, and geographic region can also affect people's risk for HIV.
What are the symptoms of HIV?The first signs of HIV infection may be flu-like symptoms:
These symptoms may come and go within two to four weeks. This stage is called acute HIV infection.
If the infection is not treated, it becomes chronic HIV infection. Often, there are no symptoms during this stage. If it is not treated, eventually the virus will weaken your body's immune system. Then the infection will progress to AIDS. This is the late stage of HIV infection. Because your immune system is badly damaged, your body cannot fight off other infections, called opportunistic infections (OIs). OIs are infections that happen more frequently or are more severe in people who have weakened immune systems.
Some people may not feel sick during the earlier stages of HIV infection. So the only way to know for sure whether you have HIV is to get tested.
How do I know if I have HIV?A blood test can tell if you have HIV infection. Your health care provider can do the test, or you can use a home testing kit. You can also use the CDC Testing Locator to find free testing sites.
What are the treatments for HIV?There is no cure for HIV infection, but it can be treated with medicines. This is called antiretroviral therapy (ART). ART can make HIV infection a manageable chronic condition. It also reduces the risk of spreading the virus to others.
Most people with HIV live long and healthy lives if they get ART as soon as possible and stay on it. It's also important to take care of yourself. Making sure that you have the support you need, living a healthy lifestyle, and getting regular medical care can help you enjoy a better quality of life.
Can HIV infection be prevented?You can reduce the risk of getting or spreading HIV by:
NIH: National Institutes of Health
What is the immune system?
Your immune system is a complex network of cells, tissues, and organs. Together they help the body fight infections and other diseases.
When germs such as bacteria or viruses invade your body, they attack and multiply. This is called an infection. The infection causes the disease that makes you sick. Your immune system protects you from the disease by fighting off the germs.
What are the parts of the immune system?The immune system has many different parts, including:
Your immune system defends your body against substances it sees as harmful or foreign. These substances are called antigens. They may be germs such as bacteria and viruses. They might be chemicals or toxins. They could also be cells that are damaged from things like cancer or sunburn.
When your immune system recognizes an antigen, it attacks it. This is called an immune response. Part of this response is to make antibodies. Antibodies are proteins that work to attack, weaken, and destroy antigens. Your body also makes other cells to fight the antigen.
Afterwards, your immune system remembers the antigen. If it sees the antigen again, it can recognize it. It will quickly send out the right antibodies, so in most cases, you don't get sick. This protection against a certain disease is called immunity.
What are the types of immunity?There are three different types of immunity:
Sometimes a person may have an immune response even though there is no real threat. This can lead to problems such as allergies, asthma, and autoimmune diseases. If you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake.
Other immune system problems happen when your immune system does not work correctly. These problems include immunodeficiency diseases. If you have an immunodeficiency disease, you get sick more often. Your infections may last longer and can be more serious and harder to treat. They are often genetic disorders.
There are other diseases that can affect your immune system. For example, HIV is a virus that harms your immune system by destroying your white blood cells. If HIV is not treated, it can lead to AIDS (acquired immunodeficiency syndrome). People with AIDS have badly damaged immune systems. They get an increasing number of severe illnesses.