The immune system is designed to defend – recognising threats, neutralising danger, and preserving balance. But when that system falters, it sometimes turns inward. The very defences meant to protect us begin to attack the body’s own tissues, triggering autoimmune conditions.
More than one hundred autoimmune conditions are now recognised, affecting millions. Yet these disorders reflect something deeper: a dysfunction at the core of immune regulation. Over time, chronic inflammation, immune exhaustion, and a loss of tolerance accelerate biological decline, undermining repair systems long before symptoms appear.
Immune system: the basics
Beyond its role as the body’s defence force, the immune system is a highly organised interconnected network, made up of specialised cells, tissues, and organs distributed throughout the body. This system is constantly active, relying on intricate communication and coordination to function effectively.
How the immune system works
White blood cells, thymus, spleen, tonsils, lymph nodes, lymph vessels, and bone marrow all play distinct roles, working in sync to respond to challenges as they arise.
When a potential threat is detected, the immune system launches a coordinated response, guided by signalling molecules known as cytokines. These proteins help immune cells communicate, ensuring that the right defences are activated at the right time.
The immune response is divided into two main branches: humoral and cellular immunity. Humoral immunity relies on soluble proteins such as antibodies and components of the complement system to identify and neutralise pathogens. Cellular immunity involves immune cells that directly target infected or abnormal cells. Together, these branches form a dynamic, adaptive system capable of defending the body against a wide range of infectious agents and abnormal cells. Dysregulation of this system leads to autoimmune diseases.
Components of the immune system
Wanting to understand the immune system in much more detail, requires knowing its core players – particularly the cells that coordinate detection, signalling and attack. Here are the three of the most critical:
White blood cells (leukocytes)
White blood cells are central to the immune response. If you’ve ever checked a blood report after an eye infection or fever, you may have noticed higher levels of these cells. Produced in the bone marrow, white blood cells travel though the bloodstream to areas of injury or infection, where they help contain and resolve threats. Elevated counts often signal that your body is actively fighting an infection.
T cells
T cells are a specialised type of white blood cells. They’re produced in the bone marrow but mature in the thymus, an immune gland in the upper chest. T cells are the system’s tacticians – identifying invaders, attacking infected cells, and orchestrating the broader immune response. There are several types, each with a distinct job: helper T cells coordinate the response, cytotoxic T cells destroy infected cells, regulatory T cells keep the system in check, and memory T cells remember past threats for quicker action in the future.
B cells
B cells, another type of white blood cells, are responsible for producing antibodies (immunoglobulins) – proteins that recognise and neutralise specific invaders like bacteria, fungi and toxins. B cells come in various forms: naïve B cells, plasma cells (which produce antibodies), memory B cells (which provide long term protection), and transitional B cells (which develop into mature B cells). Antibodies act as the immune system’s scouts and marksmen, flagging threats for destruction and preventing further harm.
What is an autoimmune condition?
Autoimmune conditions occur when the immune system loses clarity between “self” (your own cells) and “non-self” (foreign invaders). Instead of targeting only harmful microbes, it mistakenly attacks the body’s own healthy tissue and cells, treating them as threats. This misguided attack leads to inflammation and damage, which can affect almost any part of the body – depending on the condition.
Triggers and risk factors
The triggers for autoimmune conditions are many, of which genetic predisposition, environmental triggers, sex and ethnicity, and age are common.
- Genetic predisposition: A family history of autoimmune conditions increases individual risk, a strong hereditary component.
- Environmental triggers: Infections, smoking, certain chemicals, and dietary factors, all trigger autoimmune activity in genetically predisposed individuals.
- Sex and ethnicity: Autoimmune conditions are more prevalent in women, possibly due to hormonal influences (oestrogen, progesterone, androgens), and immune related genes on the X chromosome. For example, SLE is approximately 9 times more common in women than in men.
- Age: With ageing, the immune system loses its ability to distinguish between self and non-self.
While genetics does play a role in predisposing you to certain autoimmune conditions, it is solely not to be blamed, because not everyone who possesses the gene develops the disease. This indicates that external factors such as lifestyle factors (diet, movement, stress resilience, substances), environmental factors and more, also have a major role to play as opposed to the common misconception of genes being the major cause.
Stress, gut and other key players
Genes do not always carry the code for autoimmune conditions. Many other factors – heavy metal toxicity, stress, and most important of all, your gut health can impact your immunity and trigger autoimmune conditions.
Heavy metal toxicity: Heavy metals such as cadmium, arsenic, lead, copper, mercury, nickel are used in materials like paints, batteries, fertilizers, cookware and cosmetics. People are exposed to these chemicals on an everyday basis. Once exposed, these metals enter the system – either by coming in contact or inhalation and cause heavy metal toxicity. Accumulation of these chemicals, heavy metal toxins in the different tissues in the body triggers immunity.
Stress: When the body is under stress, it releases the hormone cortisol, an increasingly common physiological response in today’s high-pressure world. However, chronic physical and mental stress can compromise the immune system, increasing the risk of developing autoimmune disorders.
Leaky gut: A healthy gut holds the secret to overall health. But with erratic eating habits, intestinal infections can occur and erode the lining of the gut, leading to leaky gut. Undigested food particles, bacteria, viral and parasitic antigens enter the blood stream and trigger autoimmune conditions. In fact, it is one of the major triggers for autoimmune conditions. A leaky gut can also cause food intolerance allergies which can aggravate the concerns.
Symptoms and diagnoses
Autoimmune conditions often begin with common symptoms like persistent fatigue, low grade fevers, joint or muscle pain, skin rashes, and numbness or weakness that can easily get missed or misinterpreted to be other diseases or infections. It makes diagnosis extremely difficult. Moreover, there’s no single definitive test for autoimmune disorders. This complexity means getting a clear diagnosis often takes time and careful evaluation by healthcare professionals.
Two main categories of autoimmune conditions
Autoimmune conditions aren’t all the same – they differ in how and where the immune system misfires by identifying autoantigens. Autoantigens are either proteins or protein complexes that are present within the body, yet the immune system identifies it as foreign and triggers an immune response.
Autoimmune conditions can be broadly classified into:
Systemic autoimmune conditions
Autoimmune conditions under this category occur when the immune system identifies specific autoantigens that are present in many places – cells, tissues or organs in the body. For instance, the DNA-protein complexes (autoantigens) are found throughout the body, triggering systemic autoimmune conditions. It results in inflammation and damage which can affect multiple organs and tissues at once. Conditions like rheumatoid arthritis, systemic lupus erythematosus (SLE), Sjögren’s syndrome, scleroderma, and dermatomyositis are classic examples. These diseases are often managed by rheumatologists, and you may hear the term “rheumatic autoimmune diseases” used interchangeably with “systemic autoimmune diseases.”
Organ specific autoimmune conditions
In contrast, organ specific autoimmune conditions involve the immune system attacking specific autoantigens in a particular organ or tissue. For instance, thyroid gland in Graves’ disease, insulin producing beta cells of the pancreas in type 1 diabetes, or pigment cells in the skin in vitiligo. The effects are usually confined to the affected organ, but the impact can be profound.
Common autoimmune conditions
Autoimmune conditions can impact nearly every system in the body. Below is an overview of the most common ones, grouped by the areas they affect.
Endocrine system (hormone producing glands)
When autoimmune activity targets the endocrine system, hormone production is disrupted – affecting energy levels, metabolism, and overall function.
- Type 1 diabetes: Here, immune cells destroy the insulin producing beta cells of the pancreas. As a result, insulin secretion drops, leading to elevated blood glucose levels.
- Graves’ disease: This condition involves autoantibodies overstimulating the thyroid gland, triggering excessive production of thyroid hormones (hyperthyroidism). Common symptoms include anxiety, rapid heartbeat, weight loss, and heat intolerance.
- Hashimoto’s thyroiditis: The thyroid gland becomes the target of immune attack, resulting in reduced hormone output. People often experience fatigue, weight gain, and a slower metabolism.
Musculoskeletal system
Diseases targeting the musculoskeletal system often cause chronic pain, inflammation, and limited mobility.
- Rheumatoid arthritis (RA): A chronic inflammatory disease that affects joints on both sides of the body. It may also involve the lungs, heart, or eyes.
- Psoriatic arthritis: Linked to psoriasis, this condition is marked by joint pain, swelling, and stiffness. It can also cause inflammation at tendon or ligament attachment points (enthesitis).
- Myositis: A group of diseases caused by persistent muscle inflammation and weakness. Physical activities like walking, climbing stairs, or lifting can become difficult, and skin changes may also occur.
Digestive system
Inflammation triggered by the immune system can damage the digestive tract, interfering with nutrient absorption and gut function.
- Crohn’s disease: A form of inflammatory bowel disease (IBD) that can affect any part of the digestive tract, most commonly the terminal ileum. Symptoms include abdominal pain, diarrhoea, fatigue, and weight loss.
- Ulcerative colitis: Another type of IBD, this condition causes continuous inflammation in the colon and rectum. People often experience cramping, bloody diarrhoea, and urgency to pass stools.
- Celiac disease: Also known as gluten sensitive enteropathy, this autoimmune disorder is triggered by dietary gluten (from wheat, barley, and rye). It damages the small intestinal lining, causing villous atrophy, gastrointestinal symptoms like bloating or diarrhoea, and extraintestinal issues such as anaemia, osteoporosis, and fatigue.
Skin
Autoimmune conditions affecting the skin can alter its appearance, texture, and function, often leading to both physical discomfort and psychological distress.
- Psoriasis: The condition accelerates the life cycle of skin cells, resulting in thick, red patches with silvery scales. Commonly affects the scalp, elbows, and knees.
- Vitiligo: The immune system destroys melanocytes – the pigment-producing cells, leading to white patches on the skin. It can affect any part of the body and may progress gradually.
- Pemphigus: A rare but serious autoimmune disease that causes painful blisters and erosions on the skin and mucous membranes. It occurs due to autoantibodies attacking desmogleins, which are essential for skin cell cohesion.
Nervous system
When autoimmune responses interfere with nerve signalling, communication between the brain, spinal cord, and muscles becomes impaired.
- Multiple sclerosis (MS): The immune system attacks the myelin sheath – the protective covering of nerve fibers in the central nervous system. This impairs nerve conduction and leads to symptoms such as visual disturbances, muscle weakness, numbness, and problems with coordination and balance.
- Myasthenia gravis: Autoantibodies block receptors at the neuromuscular junction, making it difficult for nerves to trigger muscle contractions. Muscle weakness worsens with activity and often affects the eyes, face, and throat.
Systemic autoimmune conditions
These conditions are complex and far-reaching, affecting multiple organs and tissues simultaneously.
- Systemic lupus erythematosus (SLE): A highly variable disease that can affect nearly any organ, from joints and skin to kidneys and the brain. Its symptoms often resemble those of other conditions, making diagnosis difficult.
- Scleroderma: Marked by excessive collagen production, this condition causes skin tightening and hardening. It can also affect blood vessels, organs, and the gastrointestinal tract.
- Sjögren’s syndrome: This disease primarily targets moisture producing glands, leading to dry eyes and mouth. It may develop on its own or alongside other autoimmune disorders like lupus or rheumatoid arthritis.
How ageing affects the immune system
As we age, the immune system doesn’t fail all at once, but it gradually begins to lose its edge. This decline is driven by three interlinked processes: immunosenescence, inflammaging, and T cell ageing – each of which quietly alters how the body defends itself.
- Immunosenescence refers to the process in which the immune system slowly weakens, making it harder to fight infections or respond to vaccines.
- Inflammaging is the low level inflammation that increases with age. It quietly contributes to health issues like heart disease, Alzheimer’s, or even autoimmune problems.
- T cell ageing plays a crucial role in autoimmune diseases. As we get older, we have fewer new T cells and many which are much older, some of which begin to attack the body.
Together, these ageing related shifts increase the risk of autoimmune dysfunction. Conditions like giant cell arteritis and polymyalgia rheumatica often emerge after the age of 50 – the strong link between immune ageing and autoimmunity.
Decline in stem cell function
Older hematopoietic stem cells tend to make more myeloid cells (certain white blood cells that deal with inflammation) and fewer lymphoid cells (B cells and T cells that are crucial for long-term immunity). This is called a myeloid bias. This leads to an increased inflammation and decreased immune capacity. With ageing the stem cells also lose their diversity and flexibility in terms of making different types of immune cells, increasing vulnerability to infections and diseases.
The longevity connect
If left unmanaged, many autoimmune conditions can reduce both lifespan and quality of life. Chronic inflammation associated with diseases like rheumatoid arthritis, lupus, and vasculitis increases the risk of cardiovascular complications, strokes, and long-term organ damage.
Yet not all autoimmune conditions are equally severe. With early diagnosis, proper treatment, and sustained care, many individuals can live full, active lives. Managing these conditions is not just about reducing symptoms – it is about protecting long term biological performance.
Research on autoimmune conditions in older adults remains limited, especially given how ageing alters immune function. But emerging therapies are beginning to shift the landscape:
- Senolytics aim to remove senescent cells – ageing cells that drive inflammation and worsen immune dysfunction.
- Immune rejuvenation explores ways to restore immune balance, promoting longevity and reducing autoimmunity.
- Precision medicine personalises treatment based on genetics, immune profiles, and environment, moving away from one-size-fits-all approaches.
While autoimmune diseases can be challenging, they are increasingly manageable with early intervention and the right strategy. Understanding how ageing shapes immune health is key to extending both lifespan and healthspan.
Can autoimmune diseases be cured?
Most of the time, people assume that autoimmune conditions cannot be cured. But several of them can be resolved. While some conditions respond well to intervention, others are more difficult to resolve depending on the severity and organ damage.
The key lies in removing the triggers. Removing heavy metal toxins and restoring gut health can positively impact autoimmune conditions. In the body, a deficit of nutrition can hamper healthy cell replacement. A healthy gut and nutrition can reduce autoimmune conditions.
Question yourself: if the body is wired to protect itself, what causes it to turn inward? Could there be an internal imbalance making the system feel under threat?
