The immune system is a complex network of cells, tissues, organs¹ and biological processes that work together to defend the body against infections. It distinguishes between what is part of the body and what is foreign², not only eliminating harmful pathogens but also keeping a record of these invaders to respond more effectively to future threats. However, individuals with an impaired immune system may struggle to respond adequately to infections, making them more vulnerable to illness and severe complications.
What is an Impaired Immune System?
An impaired immune system is a condition in which the immune system fails to function properly. This results in a reduced ability to combat germs, leading to more frequent infections. It is commonly referred to as a weakened immune system or immunocompromised state.
While “immunocompromised” and “immunosuppressed” are often used interchangeably, they do not always mean the same thing. Although both terms refer to individuals with weakened immune systems, “immunosuppressed” is more often used to describe a person whose immune response is intentionally reduced³, such as in the case of organ transplants or autoimmune diseases.
Symptoms of an Impaired Immune System
One of the biggest indicators of an impaired immune system is experiencing more frequent or persistent illnesses. Moreover, the symptoms of immunodeficiency can vary depending on the specific disorder affecting the immune system.
Below are some common signs of an impaired immune system:
- Frequent or recurrent infections
- Severe or unusual infections
- Digestive problems
- Slow healing wounds
- Autoimmune disorders
- Fatigue
- Delayed growth or development in children
Causes of Impaired Immune Function
Many conditions can lead to a person becoming immunocompromised, with causes that can range in severity. It can result from medications, diseases and environmental factors (secondary), or acquired genetically from birth (primary/hereditary). Some of these causes include:
- HIV/AIDS: HIV attacks and destroys CD4 cells, a type of white blood cell that plays a crucial role in defending the body against illnesses and infections⁴.
- Cancer Treatments: Individuals undergoing chemotherapy and radiation for cancer may experience a significant decrease in their white blood cell count, thereby weakening the immune system.
- Cancer: Certain types of cancer can directly impact vital components of the body’s immune system. For example, lymphoma disrupts the function of lymphocytes, while leukaemia’s uncontrolled proliferation of abnormal white blood cells can lead to the displacement of healthy immune cells.
- Medications: Systemic steroids, biologics and immunosuppressive drugs⁵ prescribed for autoimmune diseases such as lupus, multiple sclerosis, type 1 diabetes, psoriasis and rheumatoid arthritis (RA) work by suppressing immune response.
- Viral Hepatitis: Viral hepatitis E (HEV) can hinder immune function through immune evasion, inhibiting immune cells and causing liver dysfunction.
- Malnutrition: An imbalance or insufficiency of essential nutrients is linked to weakened immunity. Nutrients such as vitamins (A, C, D and E), minerals (zinc, selenium and iron), and proteins play crucial roles in supporting the immune system.
- Primary Immunodeficiency (PI): Primary immunodeficiency encompasses a group of more than 450 rare, chronic conditions⁶ characterised by improper functioning of the immune system. These conditions are usually congenital (present since birth) or genetic (due to abnormalities in the genome).
- Organ or Stem Cell Transplants: These patients are likely to undergo immunosuppressive therapy to prevent organ rejection, naturally resulting in a weakened immune system.
- Stress: Chronic stress can lead to hormonal changes that negatively affect immune function.
Common Challenges of Impaired Immune Systems
It can be challenging when your immune system does not function the way it should. Individuals with a weakened immune system face an increased risk of severe illness from bacterial, fungal, viral and parasitic infections⁷ that healthy individuals can usually overcome. Furthermore, managing chronic diseases can be more difficult, as they are more susceptible to infections that those with a stronger immune system may not experience.
All these factors, combined with symptoms like fatigue, digestive problems and persistent sickness, can take a significant toll on quality of life. The emotional burden of living with immunocompromise can also heighten the risk of anxiety and depression⁸. It’s important to recognise that mental health and immune function are interconnected, as mental health issues can increase the vulnerability to physical health conditions.
An abnormal immune system also increases the risk of certain conditions due to the failure of immune surveillance over cancer cells. It is also associated with increased hypersensitivity/allergic reactions to drugs.
Management and Support for Impaired Immune Systems
Early diagnosis and intervention for an impaired immune system can lead to better outcomes, particularly by reducing the risk of infections that can cause long-term problems⁹. For infections associated with an impaired immune system, medications are prescribed based on the specific disease, and may include antibiotics for bacterial infections, antiviral medications for viral infections, and antifungal treatments for fungal infections. Recurrent infections can sometimes be managed with long term antibiotic suppression. Specific deficiencies in immunoglobulins (antibodies to fight infection) and neutrophils (white blood cells) can be managed with immunoglobulin replacement or injections (GCSF).
Your doctor may also recommend lifestyle changes to improve your immune health. A balanced diet, sufficient sleep, regular exercise, proper hygiene, and maintaining a healthy weight can all contribute to a stronger immune system. Additionally, staying up to date with vaccinations can help to prevent certain infections, even in individuals with compromised immune systems.
Learn more about infections related to impaired immunity on our page. Schedule an appointment with our specialists at ID Specialists for more information.
References
- Better Health Channel. Immune system. Victoria State Government Department of Health. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/immune-system. Accessed October 7, 2024.
- Delves P. Overview of the Immune System. MSD Manual Consumer Version. https://www.msdmanuals.com/home/immune-disorders/biology-of-the-immune-system/overview-of-the-immune-system. Accessed October 7, 2024.
- IMMUNOSUPPRESSION | Meaning in the Cambridge English Dictionary. Cambridge Dictionary. https://dictionary.cambridge.org/dictionary/english/immunosuppression. Accessed October 7, 2024.
- Human Immunodeficiency Virus (HIV). Yale Medicine. https://www.yalemedicine.org/conditions/human-immunodeficiency-virus-hiv. Accessed October 7, 2024.
- Infections Related To Impaired Immunity. ID Specialists. https://idspecialists.sg/infections-treatments/infections-related-to-impaired-immunity/. Accessed October 7, 2024.
- What is PI?. Immune Deficiency Foundation. https://primaryimmune.org/understanding-primary-immunodeficiency/what-is-pi. Accessed October 7, 2024.
- Bula-Rudas Fernando. Infections in the Immunocompromised Host: Practice Essentials, The Child with Frequent Infections, Immunocompromising Conditions. Medscape. https://emedicine.medscape.com/article/973120-overview?form=fpf. Accessed October 7, 2024.
- Mental Health Considerations in Immunocompromised Individuals. Immunize Nevada. Accessed October 7, 2024. https://immunizenevada.org/mental-health-considerations-in-immunocompromised-individuals/. Accessed October 7, 2024.
- Primary immunodeficiency. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/primary-immunodeficiency/symptoms-causes/syc-20376905. Accessed October 7, 2024.