Health Topics

Immune system

Immune System and Disorders
National Library of Medicine
Chronic Granulomatous Disease
SCID
Severe Combined Immunodeficiency

Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" invaders. Then its job is to keep them out, or if it can't, to find and destroy them.

If your immune system cannot do its job, the results can be serious. Disorders of the immune system include

  • Allergy and asthma - immune responses to substances that are usually not harmful
  • Immune deficiency diseases - disorders in which the immune system is missing one or more of its parts
  • Autoimmune diseases - diseases causing your immune system to attack your own body's cells and tissues by mistake

Immune System Diseases
Immune System
Immune System
Your immune system is a complex network of cells, tissues, and organs that work together to defend against germs. It helps your body to recognize these "foreign" ...
Immunization
National Library of Medicine
Adult Immunization
Vaccines
Vaccination

Shots may hurt a little, but the diseases they can prevent are a lot worse. Some are even life-threatening. Immunization shots, or vaccinations, are essential. They protect against things like measles, mumps, rubella, hepatitis B, polio, tetanus, diphtheria, and pertussis (whooping cough). Immunizations are important for adults as well as children.

Your immune system helps your body fight germs by producing substances to combat them. Once it does, the immune system "remembers" the germ and can fight it again. Vaccines contain germs that have been killed or weakened. When given to a healthy person, the vaccine triggers the immune system to respond and thus build immunity.

Before vaccines, people became immune only by actually getting a disease and surviving it. Immunizations are an easier and less risky way to become immune.


Vaccination
Vaccines
Immunization
Infections
Immune System
... important for adults as well as children. Your immune system helps your body fight germs by producing substances ...
HIV/AIDS Medicines
National Library of Medicine
AIDS Medicines
Antiretroviral therapy
What is HIV/AIDS?

HIV stands for human immunodeficiency virus. It harms your immune system by destroying CD4 cells. These are a type of white blood cells that fight infection. The loss of these cells makes it hard for your body to fight off infections and certain HIV-related cancers.

Without treatment, HIV can gradually destroy the immune system and advance to AIDS. AIDS stands for acquired immunodeficiency syndrome. It is the final stage of infection with HIV. Not everyone with HIV develops AIDS.

What is antiretroviral therapy (ART)?

The treatment of HIV/AIDS with medicines is called antiretroviral therapy (ART). It is recommended for everyone who has HIV. The medicines do not cure HIV infection, but they do make it a manageable chronic condition. They also reduce the risk of spreading the virus to others.

How do HIV/AIDS medicines work?

HIV/AIDS medicines reduce the amount of HIV (viral load) in your body, which helps by

  • Giving your immune system a chance to recover. Even though there is still some HIV in your body, your immune system should be strong enough to fight off infections and certain HIV-related cancers.
  • Reducing the risk that you will spread HIV to others
What are the types of HIV/AIDS medicines?

There are several different types of HIV/AIDS medicines. Some work by blocking or changing enzymes that HIV needs to make copies of itself. This prevents HIV from copying itself, which reduces the amount of HIV in the body. Several medicines do this:

  • Nucleoside reverse transcriptase inhibitors (NRTIs) block the reverse transcriptase enzyme
  • Non-nucleoside reverse transcriptase inhibitors (NNRTIs) bind to and later change the reverse transcriptase enzyme
  • Integrase inhibitors block the integrase enzyme
  • Protease inhibitors (PIs) block the protease enzyme

Some HIV/AIDS medicines interfere with HIV's ability to infect CD4 immune system cells:

  • Fusion inhibitors block HIV from entering the cells
  • CCR5 antagonists and post-attachment inhibitors block different molecules on the CD4 cells. To infect a cell, HIV has to bind to two types of molecules on the cell's surface. Blocking either of these molecules prevents HIV from entering the cells.

In some cases, people take more than one medicine:

  • Pharmacokinetic enhancers boost the effectiveness of certain HIV/AIDS medicines. A pharmacokinetic enhancer slows the breakdown of the other medicine. This allows that medicine to stay in the body longer at a higher concentration.
  • Multidrug combinations include a combination of two or more different HIV/AIDS medicines
When do I need to start taking HIV/AIDS medicines?

It's important to start taking HIV/AIDS medicines as soon as possible after your diagnosis, especially if you

  • Are pregnant
  • Have AIDS
  • Have certain HIV-related illnesses and infections
  • Have an early HIV infection (the first 6 months after infection with HIV)
What else do I need to know about taking HIV/AIDS medicines?

It's important to take your medicines every day, according to the instructions from your health care provider. If you miss doses or don't follow a regular schedule, your treatment may not work and the HIV virus may become resistant to the medicines.

HIV medicines can cause side effects. Most of these side effects are manageable, but a few can be serious. Tell your health care provider about any side effects you are having. Don't stop taking your medicine without first talking to your provider. He or she may give you tips on how to deal with the side effects. In some cases, your provider may decide to change your medicines.

AIDSinfo


HIV Infections
Antiretroviral Therapy, Highly Active
Anti-HIV Agents
Immune System
Drug Therapy
... stands for human immunodeficiency virus. It harms your immune system by destroying CD4 cells. These are a type of white blood cells that fight infection. The loss of these cells makes it ... gradually destroy the immune system and advance to AIDS. AIDS stands for ...
Shingles
National Library of Medicine
Herpes Zoster
Post-herpetic Neuralgia
Postherpetic neuralgia
What is shingles?

Shingles is an outbreak of rash or blisters on the skin. It is caused by the varicella-zoster virus - the same virus that causes chickenpox. After you have chickenpox, the virus stays in your body. It may not cause problems for many years. But as you get older, the virus may reappear as shingles.

Is shingles contagious?

Shingles is not contagious. But you can catch chickenpox from someone with shingles. If you've never had chickenpox or the chickenpox vaccine, try to stay away from anyone who has shingles.

If you have shingles, try to stay away from anyone who has not had chickenpox or the chickenpox vaccine, or anyone who might have a weak immune system.

Who is at risk for shingles?

Anyone who has had chickenpox is at risk for getting shingles. But this risk goes up as you get older; shingles is most common in people over age 50.

People with weakened immune systems are at higher risk of getting shingles. This includes those who

  • Have immune system diseases such as HIV/AIDS
  • Have certain cancers
  • Take immunosuppressive drugs after an organ transplant

Your immune system may be weaker when you have an infection or are stressed. This can raise your risk of shingles.

It is rare, but possible, to get shingles more than once.

What are the symptoms of shingles?

Early signs of shingles include burning or shooting pain and tingling or itching. It is usually on one side of the body or face. The pain can be mild to severe.

One to 14 days later, you will get a rash. It consists of blisters that typically scab over in 7 to 10 days. The rash is usually a single stripe around either the left or the right side of the body. In other cases, the rash occurs on one side of the face. In rare cases (usually among people with weakened immune systems), the rash may be more widespread and look similar to a chickenpox rash.

Some people may also have other symptoms:

  • Fever
  • Headache
  • Chills
  • Upset stomach
What other problems can shingles cause?

Shingles can cause complications:

  • Postherpetic neuralgia (PHN) is most common complication of shingles. It causes severe pain in the areas where you had the shingles rash. It usually gets better in a few weeks or months. But some people can have pain from PHN for many years, and it can interfere with daily life.
  • Vision loss can happen if shingles affects your eye. It may be temporary or permanent.
  • Hearing or balance problems are possible if you have shingles within or near your ear. You may also have weakness of the muscles on that side of your face. These problems can be temporary or permanent.

Very rarely, shingles can also lead to pneumonia, brain inflammation (encephalitis), or death.

How is shingles diagnosed?

Usually your health care provider can diagnose shingles by taking your medical history and looking at your rash. In some cases, your provider may scrap off tissue from the rash or swab some fluid from the blisters and send the sample to a lab for testing.

What are the treatments for shingles?

There is no cure for shingles. Antiviral medicines may help to make the attack shorter and less severe. They may also help prevent PHN. The medicines are most effective if you can take them within 3 days after the rash appears. So if you think you might have shingles, contact your health care provider as soon as possible.

Pain relievers may also help with the pain. A cool washcloth, calamine lotion, and oatmeal baths may help relieve some of the itching.

Can shingles be prevented?

There are vaccines to prevent shingles or lessen its effects. The Centers for Disease Control and Prevention recommends that healthy adults 50 years and older get the Shingrix vaccine. You need two doses of the vaccine, given 2 to 6 months apart. Another vaccine, Zostavax, may be used in certain cases.


Neuralgia, Postherpetic
Herpes Zoster
Older Adults
Infections
Brain and Nerves
Skin, Hair and Nails
... vaccine, or anyone who might have a weak immune system.Who is at risk for shingles? Anyone who has had chickenpox is at risk for getting shingles. But this risk goes up as you ... with weakened immune systems are at higher risk of getting shingles. ...
Cancer Immunotherapy
National Library of Medicine

Immunotherapy is a cancer treatment that helps your immune system fight cancer. It is a type of biological therapy. Biological therapy uses substances that are made from living organisms, or versions of these substances that are made in a lab.

Doctors don't yet use immunotherapy as often as other cancer treatments, such as surgery, chemotherapy, and radiation therapy. But they do use immunotherapy for some types of cancer, and researchers are doing clinical trials to see whether it also works for other types.

When you have cancer, some of your cells begin to multiply without stopping. They spread into the surrounding tissues. One reason that the cancer cells can keep growing and spreading is that they are able to hide from your immune system. Some immunotherapies can "mark" your cancer cells. This makes it easier for your immune system to find and destroy the cells. It is a type of targeted therapy, which uses drugs or other substances that attack specific cancer cells with less harm to normal cells. Other types of immunotherapies work by boosting your immune system to work better against cancer.

You could get immunotherapy intravenously (by IV), in pills or capsules, or in a cream for your skin. For bladder cancer, they might place it directly into your bladder. You may have treatment every day, week, or month. Some immunotherapies are given in cycles. It depends on your type of cancer, how advanced it is, the type of immunotherapy you get, and how well it is working.

You may have side effects. The most common side effects are skin reactions at the needle site, if you get it by IV. Other side effects may include flu-like symptoms, or rarely, severe reactions.

NIH: National Cancer Institute


Neoplasms
Immunotherapy
Cancers
Immunotherapy is a cancer treatment that helps your immune system fight cancer. It is a type of biological ... that they are able to hide from your immune system. Some immunotherapies can "mark" your cancer cells. This ...
Autoimmune Diseases
National Library of Medicine
Autoinflammatory Disorders

Your body's immune system protects you from disease and infection. But if you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake. Autoimmune diseases can affect many parts of the body.

No one is sure what causes autoimmune diseases. They do tend to run in families. Women - particularly African-American, Hispanic-American, and Native-American women - have a higher risk for some autoimmune diseases.

There are more than 80 types of autoimmune diseases, and some have similar symptoms. This makes it hard for your health care provider to know if you really have one of these diseases, and if so, which one. Getting a diagnosis can be frustrating and stressful. Often, the first symptoms are fatigue, muscle aches and a low fever. The classic sign of an autoimmune disease is inflammation, which can cause redness, heat, pain and swelling.

The diseases may also have flare-ups, when they get worse, and remissions, when symptoms get better or disappear. Treatment depends on the disease, but in most cases one important goal is to reduce inflammation. Sometimes doctors prescribe corticosteroids or other drugs that reduce your immune response.


Autoimmune Diseases
Immune System
Your body's immune system protects you from disease and infection. But if you have an autoimmune disease, your immune system attacks healthy cells in your body by mistake. Autoimmune diseases can affect many parts of the body. No ...
Skin Infections
National Library of Medicine
Molluscum Contagiosum
What are skin infections?

Your skin is your body's largest organ. It has many different functions, including covering and protecting your body. It helps keep germs out. But sometimes the germs can cause a skin infection. This often happens when there is a break, cut, or wound on your skin. It can also happen when your immune system is weakened, because of another disease or a medical treatment.

Some skin infections cover a small area on the top of your skin. Other infections can go deep into your skin or spread to a larger area.

What causes skin infections?

Skin infections are caused by different kinds of germs. For example,

  • Bacteria cause cellulitis, impetigo, and staphylococcal (staph) infections
  • Viruses cause shingles, warts, and herpes simplex
  • Fungi cause athlete's foot and yeast infections
  • Parasites cause body lice, head lice, and scabies
Who is at risk for skin infections?

You are at a higher risk for a skin infection if you

  • Have poor circulation
  • Have diabetes
  • Are older
  • Have an immune system disease, such as HIV/AIDS
  • Have a weakened immune system because of chemotherapy or other medicines that suppress your immune system
  • Have to stay in one position for a long time, such as if you are sick and have to stay in bed for a long time or you are paralyzed
  • Are malnourished
  • Have excessive skinfolds, which can happen if you have obesity
What are the symptoms of skin infections?

The symptoms depend on the type of infection. Some symptoms that are common to many skin infections include rashes, swelling, redness, pain, pus, and itching.

How are skin infections diagnosed?

To diagnose a skin infection, health care providers will do a physical exam and ask about your symptoms. You may have lab tests, such as a skin culture. This is a test to identify what type of infection you have, using a sample from your skin. Your provider may take the sample by swabbing or scraping your skin, or removing a small piece of skin (biopsy). Sometimes providers use other tests, such as blood tests.

How are skin infections treated?

The treatment depends on the type of infection and how serious it is. Some infections will go away on their own. When you do need treatment, it may include a cream or lotion to put on the skin. Other possible treatments include medicines and a procedure to drain pus.


Skin Diseases, Infectious
Infections
Skin, Hair and Nails
... your skin. It can also happen when your immune system is weakened, because of another disease or a ... poor circulation Have diabetes Are older Have an immune system disease, such as HIV/AIDS Have a weakened ...
Pneumocystis Infections
National Library of Medicine

Pneumocystis jirovecii is a tiny fungus that lives in the lungs of many people. Most people's immune systems keep the fungus under control. But if you have a weakened immune system, the fungus can make you very sick.

The most common type of infection is pneumocystis pneumonia (PCP). PCP once was the major cause of death for people with HIV/AIDS. But now, it is possible to prevent or treat most cases. The key to surviving PCP is early treatment. The first signs of PCP are fever, dry cough, shortness of breath, and fatigue. If you have a weakened immune system and have these symptoms, see your doctor right away.

To diagnose PCP, doctors use a microscope to look for the fungus in a sample of lung fluid or tissue. Treatment is with antibiotics.

There is no vaccine to prevent PCP. Some people who are at high risk of getting PCP may need to take antibiotics to prevent it.


Pneumocystis Infections
Infections
Lungs and Breathing
Immune System
... in the lungs of many people. Most people's immune systems keep the fungus under control. But if you have a weakened immune system, the fungus can make you very sick. ...
Lupus
National Library of Medicine
SLE
Systemic Lupus Erythematosus
Discoid lupus
Subacute cutaneous lupus
What is lupus?

Lupus is an autoimmune disease. This means that your immune system attacks healthy cells and tissues by mistake. This can damage many parts of the body, including the joints, skin, kidneys, heart, lungs, blood vessels, and brain.

There are several kinds of lupus

  • Systemic lupus erythematosus (SLE) is the most common type. It can be mild or severe, and can affect many parts of the body.
  • Discoid lupus causes a red rash that doesn't go away
  • Subacute cutaneous lupus causes sores after being out in the sun
  • Drug-induced lupus is caused by certain medicines. It usually goes away when you stop taking the medicine.
  • Neonatal lupus, which is rare, affects newborns. It is probably caused by certain antibodies from the mother.
What causes lupus?

The cause of lupus is unknown.

Who is at risk for lupus?

Anyone can get lupus, but women are most at risk. Lupus is two to three times more common in African American women than in Caucasian women. It's also more common in Hispanic, Asian, and Native American women. African American and Hispanic women are more likely to have severe forms of lupus.

What are the symptoms of lupus?

Lupus can have many symptoms, and they differ from person to person. Some of the more common ones are

  • Pain or swelling in joints
  • Muscle pain
  • Fever with no known cause
  • Red rashes, most often on the face (also called the "butterfly rash")
  • Chest pain when taking a deep breath
  • Hair loss
  • Pale or purple fingers or toes
  • Sensitivity to the sun
  • Swelling in legs or around eyes
  • Mouth ulcers
  • Swollen glands
  • Feeling very tired

Symptoms may come and go. When you are having symptoms, it is called a flare. Flares can range from mild to severe. New symptoms may appear at any time.

How is lupus diagnosed?

There is no specific test for lupus, and it's often mistaken for other diseases. So it may take months or years for a doctor to diagnose it. Your doctor may use many tools to make a diagnosis:

  • Medical history
  • Complete exam
  • Blood tests
  • Skin biopsy (looking at skin samples under a microscope)
  • Kidney biopsy (looking at tissue from your kidney under a microscope)
What are the treatments for lupus?

There is no cure for lupus, but medicines and lifestyle changes can help control it.

People with lupus often need to see different doctors. You will have a primary care doctor and a rheumatologist (a doctor who specializes in the diseases of joints and muscles). Which other specialists you see depends on how lupus affects your body. For example, if lupus damages your heart or blood vessels, you would see a cardiologist.

Your primary care doctor should coordinate care between your different health care providers and treat other problems as they come up. Your doctor will develop a treatment plan to fit your needs. You and your doctor should review the plan often to be sure it is working. You should report new symptoms to your doctor right away so that your treatment plan can be changed if needed.

The goals of the treatment plan are to

  • Prevent flares
  • Treat flares when they occur
  • Reduce organ damage and other problems

Treatments may include drugs to

  • Reduce swelling and pain
  • Prevent or reduce flares
  • Help the immune system
  • Reduce or prevent damage to joints
  • Balance the hormones

Besides taking medicines for lupus, you may need to take medicines for problems that are related to lupus such as high cholesterol, high blood pressure, or infection.

Alternative treatments are those that are not part of standard treatment. At this time, no research shows that alternative medicine can treat lupus. Some alternative or complementary approaches may help you cope or reduce some of the stress associated with living with a chronic illness. You should talk to your doctor before trying any alternative treatments.

How can I cope with lupus?

It is important to take an active role in your treatment. It helps to learn more about lupus - being able to spot the warning signs of a flare can help you prevent the flare or make the symptoms less severe.

It is also important to find ways to cope with the stress of having lupus. Exercising and finding ways to relax may make it easier for you to cope. A good support system can also help.

NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases


Lupus Erythematosus, Systemic
Lupus Erythematosus, Discoid
Immune System
... easier for you to cope. A good support system can also help. NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
Allergy
National Library of Medicine
Allergic Rhinitis
Hypersensitivity

An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are

  • Pollen
  • Dust mites
  • Mold spores
  • Pet dander
  • Food
  • Insect stings
  • Medicines

Normally, your immune system fights germs. It is your body's defense system. In most allergic reactions, however, it is responding to a false alarm. Genes and the environment probably both play a role.

Allergies can cause a variety of symptoms such as a runny nose, sneezing, itching, rashes, swelling, or asthma. Allergies can range from minor to severe. Anaphylaxis is a severe reaction that can be life-threatening. Doctors use skin and blood tests to diagnose allergies. Treatments include medicines, allergy shots, and avoiding the substances that cause the reactions.


Hypersensitivity
Ear, Nose and Throat
Immune System
An allergy is a reaction by your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that ...