Immune Disorders
When the immune system is too weak, overactive, or misdirected
Quick Facts
- Type: Immune system conditions
- Main categories: Immunodeficiency, autoimmune, allergic
- Common examples: Allergies, lupus, primary immunodeficiency
- Seek emergency care: Severe allergic reaction with breathing trouble
Overview
Immune disorders are conditions that affect the body's defense system, which normally protects against infections and other threats. When the immune system does not work properly, it can be too weak to fight off germs, overactive so that it reacts to harmless substances, or misdirected so that it attacks the body's own healthy tissues. These problems give rise to several different families of disease.
The main categories are immunodeficiency disorders, in which the immune response is too weak; autoimmune disorders, in which the immune system attacks the body itself; and allergic or hypersensitivity disorders, in which the immune system overreacts to harmless triggers. Some immune disorders are inherited, while others develop later in life. Many are long-term conditions that can be managed effectively with treatment.
Symptoms
Symptoms vary widely depending on which type of immune disorder is present and which organs are involved.
- Weak immunity (immunodeficiency): frequent, severe, or unusual infections, slow recovery, and poor response to standard treatment
- Autoimmune disorders: fatigue, joint pain and swelling, skin rashes, fevers, and symptoms that come and go in flares
- Allergic disorders: sneezing, itchy or watery eyes, hives, swelling, wheezing, and digestive upset after exposure to a trigger
A severe allergic reaction (anaphylaxis) can cause throat swelling, difficulty breathing, a drop in blood pressure, and collapse, and is a medical emergency.
Causes
Immune disorders arise from problems in how the immune system develops or behaves.
- Inherited gene changes: primary immunodeficiencies are present from birth due to faulty genes affecting immune cells.
- Acquired immunodeficiency: infections such as HIV, certain cancers, chemotherapy, and immune-suppressing medications can weaken the immune system.
- Autoimmune triggers: a mix of genetic tendency and environmental factors, such as infections or hormones, can lead the immune system to attack the body.
- Allergic sensitization: the immune system mistakenly treats harmless substances such as pollen or foods as threats.
Risk Factors
- A family history of immune, autoimmune, or allergic conditions
- HIV infection or other conditions that weaken immunity
- Long-term use of immune-suppressing medications or chemotherapy
- Female sex, which is associated with several autoimmune diseases
- Certain infections that can trigger immune reactions
- Environmental exposures and allergens
Diagnosis
Diagnosing an immune disorder involves identifying the pattern of immune dysfunction and the organs affected.
- Medical history and examination: patterns such as recurrent infections, flares of joint or skin symptoms, or reactions to triggers guide testing.
- Blood tests: counts of immune cells, antibody levels, and markers of inflammation.
- Autoantibody tests: detect antibodies directed against the body's own tissues in autoimmune disease.
- Allergy testing: skin or blood tests to identify specific allergic triggers.
- Specialized immune tests: assess how well immune cells respond, especially in suspected immunodeficiency.
Treatment
Treatment depends on the specific disorder and aims to correct, calm, or redirect the immune response.
- For weak immunity: treating underlying causes, preventing and promptly treating infections, and in some cases immunoglobulin replacement to supply missing antibodies.
- For autoimmune disease: anti-inflammatory drugs, corticosteroids, and immune-suppressing or targeted biologic medications to reduce attacks on the body.
- For allergies: avoiding triggers, antihistamines, and, for some people, allergy shots (immunotherapy) and emergency adrenaline for severe reactions.
- Vaccination and infection prevention: important for many people with immune disorders, guided by a specialist.
Care is often provided by an immunologist, rheumatologist, or allergist depending on the type of disorder.
Prevention
Many immune disorders cannot be prevented, but several steps reduce risk and complications.
- Practice good hygiene and stay up to date with recommended vaccinations
- Avoid known allergens and carry prescribed emergency medication if you have severe allergies
- Take immune-suppressing medications exactly as directed and report infections early
- Manage chronic conditions and attend regular follow-up appointments
- Seek genetic counseling if there is a strong family history of inherited immune disease
When to See a Doctor
See a doctor for frequent or severe infections, unexplained fatigue with joint pain or rashes, or recurring allergic symptoms. Call emergency services immediately for signs of a severe allergic reaction (anaphylaxis), including:
- Swelling of the lips, tongue, or throat
- Difficulty breathing or wheezing
- A widespread rash or hives with dizziness or fainting
- A rapid, weak pulse or sudden collapse after exposure to an allergen
Frequently Asked Questions
What are the main types of immune disorders?
There are three main groups: immunodeficiency disorders, where the immune system is too weak to fight infection; autoimmune disorders, where it attacks the body's own tissues; and allergic disorders, where it overreacts to harmless substances. Some people have features of more than one.
Are immune disorders inherited?
Some are. Primary immunodeficiencies are inherited and present from birth. Many autoimmune and allergic disorders involve a genetic tendency combined with environmental triggers, while others, such as HIV-related immunodeficiency, are acquired during life.
Can immune disorders be cured?
Most are managed rather than cured. Allergies, autoimmune diseases, and immunodeficiencies can often be well controlled with treatment to reduce symptoms, prevent flares, and avoid complications. A specialist tailors treatment to the specific condition.
What is anaphylaxis and why is it dangerous?
Anaphylaxis is a severe, rapid allergic reaction that can cause throat swelling, difficulty breathing, and a dangerous drop in blood pressure. It is a medical emergency. People at risk should carry emergency adrenaline and call emergency services if it occurs.
How are immune disorders diagnosed?
Doctors use the medical history and examination along with blood tests that measure immune cells, antibody levels, and markers of inflammation. Autoantibody and allergy tests and specialized immune function tests help pinpoint the exact disorder.
References
- National Institute of Allergy and Infectious Diseases (NIAID). Immune System Disorders.
- MedlinePlus, U.S. National Library of Medicine. Immune System and Disorders.
- American Academy of Allergy, Asthma & Immunology. Immune Deficiencies.
- Mayo Clinic. Autoimmune diseases — Overview.