22-07-2025
Immunodeficiency Disorders
Immunodeficiency disorders prevent your body from fighting infections and diseases as well as it should. This type of disorder can make it easier for you to develop viral or bacterial infections.
Key points
Immunodeficiency disorders affect your body's ability to defend itself against bacteria, viruses, and parasites.
There are two types of immunodeficiency disorders: those you are born with (primary) and those that are acquired (secondary).
Anything that weakens your immune system may lead to a secondary immunodeficiency disorder.
Immunodeficiency disorders are either congenital or acquired. A congenital, or primary, disorder is one you were born with. An acquired, or secondary, disorder is one you get later in life. Acquired disorders are more common than congenital disorders.
Your immune system includes the following organs:
spleen
tonsils
bone marrow
lymph nodes
These organs create and release lymphocytes, which are white blood cells classified as B cells and T cells.
B and T cells fight invaders by detecting specific parts of them known as 'antigens.' B cells release antibodies specific to the antigen that your body detects. T cells can destroy foreign or atypical cells.
Your B and T cells might need to fight off:
bacteria
viruses
cancer cells
parasites
An immunodeficiency disorder disrupts your body's ability to defend itself against these.
What is a weak immune system?
If you have a 'weaker' immune system, it means your body is immunocompromised. This means your body can't fight off infections or viruses as well as people who are not immunocompromised.
While a weaker immune system is typically caused by certain diseases, malnutrition, and certain genetic disorders, it may also be temporary, as a result of medications such as anticancer drugs and radiation therapy.
Your immune system can also be temporarily weakened by a stem cell or organ transplant.
Signs of an immunodeficiency disorder
There are hundreds of types of immunodeficiency disorders. Each disorder has unique symptoms that can be frequent or chronic. However, there are a few warning signs that something may be going on with your immune system.
Individuals with immunodeficiency disorders tend to have frequent infections — one round after another — of certain conditions, such as:
pink eye
sinus infections
thrush
colds
chronic gum disease (gingivitis)
pneumonia
yeast infections
Individuals with immunodeficiency disorders may also develop chronic abdominal pain, and they may even lose weight over time.
If you find that you get sick easily and have a hard time shaking off viruses and other infections, your doctor might suggest you get tested for an immunodeficiency disorder.
What are the different types of immunodeficiency disorders?
An immune deficiency disease or disorder occurs when the immune system is not working as expected. If you're born with a deficiency from a genetic cause, it's called primary immunodeficiency disease. There are more than 200 primary immunodeficiency disorders.
Examples of primary immunodeficiency disorders include:
common variable immunodeficiency (CVID)
severe combined immunodeficiency (SCID), which is also known as alymphocytosis
chronic granulomatous disease (CGD)
Secondary immunodeficiency disorders happen when an outside source, like a chemical or infection, weakens your body. The following can cause a secondary immunodeficiency disorder:
severe burns
chemotherapy
radiation
diabetes mellitus
malnutrition
Examples of secondary immunodeficiency disorders include:
stage 3 HIV
cancers of the immune system, like leukemia
immune-complex diseases, like viral hepatitis
multiple myeloma (cancer of the plasma cells, a type of B cell that produces antibodies)
Causes and risk factors
Primary immunodeficiency disorders are most commonly caused by inherited gene mutations.
People who have a family history of primary immunodeficiency disorders have a higher risk of developing primary disorders themselves.
Secondary immunodeficiency disorders can be caused by a variety of things, including:
chronic conditions (like diabetes or cancer)
drugs
radiation therapy (this is rare)
long-term hospitalization
insufficient nutrition
Anything that weakens your immune system can lead to a secondary immunodeficiency disorder. For example, exposure to body fluids containing HIV or organ removal and replacement can both be causes.
Aging can also weaken your immune system. As you age, some of the organs that produce or process white blood cells shrink and become less efficient.
Proteins are important for your immunity. Not getting enough protein in your diet can weaken your immune system.
Your body also produces proteins when you sleep that help your body fight infection. For this reason, lack of sleep can reduce your immune defenses.
Cancers and chemotherapy drugs can also reduce your immunity.
How are immune disorders diagnosed?
If your doctor thinks you might have an immunodeficiency disorder, they may:
ask you about your medical history
perform a physical exam
check your overall white blood cell count
determine your T cell count
measure your immunoglobulin levels
Your doctor may also perform a skin test, which is usually done when a T-cell abnormality is suspected.
During a skin test, a small number of proteins from common infectious organisms (like yeast) are injected right under the skin. If there's no reaction (such as swelling or redness) within 2 days, that can be a sign of an immunodeficiency disorder from a T-cell abnormality.
Biopsies of the lymph nodes or bone marrow may also be performed to help your doctor narrow down which disorder may be causing your symptoms.
A doctor may also recommend genetic testing, usually via a blood test, to determine if there are any gene mutations that may be causing your immunodeficiency disorder.
How are immunodeficiency disorders treated?
Treating immunodeficiency disorders typically involves:
preventing infections when possible
treating infections when they occur
strengthening parts of your immune system
Antibiotics and immunoglobulin therapy are two types of medications often used in treatment.
Other antiviral drugs, like oseltamivir, acyclovir, or interferon, are sometimes used to treat viral infections caused by immunodeficiency disorders.
If your bone marrow isn't producing enough lymphocytes, your doctor might suggest a bone marrow (stem cell) transplant.
Can immunodeficiency disorders be prevented?
Primary immunodeficiency disorders can be managed and treated, but they can't be prevented.
The risk of developing secondary disorders can sometimes be lowered through lifestyle choices. For example, it's possible to lower your risk of developing type 2 diabetes by eating a nutritious diet and getting enough physical activity.
Sleep is very important for a healthy immune system. According to the CDC, long-term sleep loss may lead to a variety of chronic conditions and weaken the body's ability to fight infections.
What type of doctor treats immunodeficiency disorders?
If your primary care physician has diagnosed you with an immunodeficiency disorder or suspects you might have one and wants an expert opinion, they will most likely send you to an immunologist.
Immunologists specialize in immunodeficiency disorders. Typically, after gaining a bachelor's degree, individuals who want to become immunologists must go through 9 years of additional medical training.
To be board certified, they must pass an exam by the American Board of Allergy and Immunology (ABAI).