An autoimmune disease happens when your immune system mistakenly attacks your own body. Instead of fighting germs and viruses, it targets healthy cells and tissues. This can affect almost any organ or system in your body. In this article, we explain what autoimmune diseases are, the most common types, symptoms to watch for, and how they are treated in Canada.
What Is an Autoimmune Disease?
Your immune system is your body’s defence network. It normally identifies harmful invaders — like bacteria and viruses — and destroys them. However, in people with an autoimmune disease, the immune system gets confused. It treats healthy tissues as if they were threats and launches an attack against them.
This misdirected immune response can cause inflammation, pain, and organ damage. The damage can be mild or severe, depending on which part of the body is affected. Some autoimmune diseases target a single organ. Others affect the entire body.
Researchers have identified more than 80 different autoimmune diseases. They are more common than most people realize. In fact, autoimmune conditions affect millions of Canadians. Women are diagnosed more often than men, though anyone can develop these conditions at any age.
What Causes an Autoimmune Disease?
Scientists do not fully understand what causes the immune system to attack the body. However, research points to a combination of genetic and environmental factors. If a close family member has an autoimmune disease, your own risk may be higher.
Environmental triggers may also play a role. These can include infections, certain medications, and exposure to chemicals or toxins. Furthermore, hormonal changes — particularly in women — may influence the immune system’s behaviour. This may help explain why women develop autoimmune conditions more often than men.
Stress is another factor that researchers are studying. Chronic stress can affect how well the immune system regulates itself. As a result, prolonged stress may contribute to flare-ups or even trigger the onset of certain conditions. For example, some people notice their symptoms worsen during stressful periods in their lives.
Risk Factors to Know
Certain factors can increase your chance of developing an autoimmune disease. These include:
Family history: Having a parent or sibling with an autoimmune condition raises your risk.
Sex: Women are significantly more likely to develop many autoimmune diseases.
Age: Many autoimmune diseases are diagnosed in adults between 15 and 44 years old.
Smoking: Tobacco use has been linked to several autoimmune conditions.
Obesity: Excess body weight may increase inflammation and immune dysfunction.
Infections: Some viral or bacterial infections may trigger autoimmune responses in certain people.
Having one or more of these risk factors does not mean you will develop an autoimmune disease. However, it is useful information to share with your family doctor or healthcare provider.
Common Types of Autoimmune Disease
There are many different autoimmune diseases. They are often grouped based on whether they affect one specific organ or the whole body. Understanding these two broad categories can help make sense of how widely these conditions vary.
Organ-Specific Autoimmune Diseases
Some autoimmune diseases target one particular organ. The immune system focuses its attack on a specific tissue or gland. Here are some well-known examples:
Hashimoto’s thyroiditis: The immune system attacks the thyroid gland. This leads to an underactive thyroid (hypothyroidism), which can cause fatigue, weight gain, and cold sensitivity.
Type 1 diabetes: The immune system destroys insulin-producing cells in the pancreas. Without insulin, blood sugar levels rise dangerously high.
Myasthenia gravis: This condition affects the communication between nerves and muscles. It leads to muscle weakness, especially in the eyes, face, and throat.
Multiple sclerosis (MS): The immune system attacks the protective coating around nerve fibres in the brain and spinal cord. Canada has one of the highest rates of MS in the world.
Systemic Autoimmune Diseases
Other autoimmune diseases affect multiple organs or systems throughout the body. These are sometimes called connective tissue diseases or systemic conditions. They tend to be more complex and harder to diagnose.
Lupus (Systemic Lupus Erythematosus): Lupus can affect the skin, joints, kidneys, heart, and brain. It often causes a butterfly-shaped rash across the cheeks and nose.
Rheumatoid arthritis: The immune system attacks the lining of the joints, causing pain, swelling, and stiffness. It can also affect the heart and lungs over time.
Dermatomyositis and polymyositis: These conditions involve immune attacks on the muscles. They can cause muscle weakness and skin changes.
Sjögren’s syndrome: This condition targets moisture-producing glands. It leads to dry eyes and dry mouth and can affect other organs.
For a more complete list of autoimmune conditions, you can visit Healthline’s guide to autoimmune disorders.
Symptoms of Autoimmune Disease
Because autoimmune diseases affect so many different parts of the body, symptoms vary widely. However, many people with an autoimmune disease experience some common early warning signs.
These shared symptoms often come and go. Periods when symptoms worsen are called flare-ups. Periods when symptoms improve or disappear are called remissions. This pattern of flares and remissions is typical of many autoimmune conditions.
Common Early Symptoms
Persistent fatigue that does not improve with rest
Joint pain, swelling, or stiffness
Recurring low-grade fever
Skin rashes or unusual skin changes
Swollen glands or lymph nodes
Digestive problems, including cramping or bloating
Hair loss or thinning
Muscle weakness or aching
Difficulty concentrating (sometimes called “brain fog”)
Numbness or tingling in the hands and feet
These symptoms can also be signs of many other health conditions. Therefore, experiencing them does not necessarily mean you have an autoimmune disease. A proper diagnosis from a healthcare provider is essential.
How Is an Autoimmune Disease Diagnosed?
Diagnosing an autoimmune disease can be challenging. Many conditions share overlapping symptoms, and there is no single test that identifies all autoimmune diseases. Diagnosis often involves a combination of steps.
Your doctor will typically start with a thorough review of your medical history and a physical exam. They will ask about your symptoms, how long you have had them, and whether anyone in your family has a similar condition.
Tests Your Doctor May Order
Several laboratory and imaging tests can help detect autoimmune activity in the body. These may include:
Antinuclear antibody (ANA) test: This blood test checks for antibodies that attack the body’s own cells. A positive ANA can indicate several different autoimmune diseases.
Complete blood count (CBC): This test measures different types of blood cells. Abnormal levels can point to inflammation or immune system problems.
Erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP): These blood tests measure general inflammation in the body.
Specific antibody tests: For example, anti-thyroid antibodies help diagnose Hashimoto’s thyroiditis, while anti-CCP antibodies help confirm rheumatoid arthritis.
Imaging tests: X-rays, MRIs, or ultrasounds can reveal joint damage, organ changes, or inflammation.
Getting to a diagnosis may take time. In some cases, people see multiple specialists before receiving a clear answer. In Canada, your family doctor can coordinate referrals to rheumatologists, neurologists, or other specialists covered under your provincial health plan.
You can also learn more about how these conditions are diagnosed through Mayo Clinic’s overview of autoimmune disease diagnosis and treatment.
Treatment Options for Autoimmune Disease
There is currently no cure for most autoimmune diseases. However, treatments have improved significantly over the years. Most treatment plans focus on controlling symptoms, reducing inflammation, and slowing damage to the body.
The right treatment depends on the specific condition, its severity, and how it affects daily life. Your healthcare team will work with you to find the best approach for your situation.
Medications Commonly Used
Doctors use several types of medication to manage autoimmune conditions. The most common include:
Corticosteroids: These anti-inflammatory drugs — such as prednisone — are widely used during flare-ups. They reduce immune activity quickly but can cause side effects with long-term use.
Immunosuppressants: These medications calm down an overactive immune system. They are often used when corticosteroids alone are not enough. Examples include methotrexate and azathioprine.
Biologics: These are newer, targeted therapies. They block specific parts of the immune response. Biologics have transformed treatment for conditions like rheumatoid arthritis and lupus.
Pain relievers: Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen can help manage joint pain and inflammation.
Hormone replacement: For conditions like type 1 diabetes or hypothyroidism, replacing the missing hormone (insulin or thyroid hormone) is essential.
Plasmapheresis
In some severe cases, doctors may recommend plasmapheresis (also called plasma exchange). This procedure removes harmful antibodies from the blood. It works by filtering the liquid part of your blood — the plasma — and replacing it with clean fluid. However, this treatment is typically reserved for specific and serious situations.
Lifestyle and Self-Care
Alongside medication, healthy lifestyle habits can make a real difference in managing an autoimmune disease. Consider these strategies:
Eat a balanced, anti-inflammatory diet rich in vegetables, fruits, whole grains, and fibre.
Exercise regularly, within your comfort level. Even gentle movement like walking or swimming can reduce inflammation.
Get enough quality sleep each night. Poor sleep can worsen immune dysfunction and fatigue.
Manage stress through techniques like mindfulness, yoga, or deep breathing.
Avoid smoking and limit alcohol. Both can trigger flare-ups and worsen symptoms.
Stay up to date with vaccinations, as recommended by your doctor. Some autoimmune treatments suppress the immune system, making infections more dangerous.
The Health Canada website offers resources to help Canadians manage chronic conditions and find support programmes in their province.
Living With an Autoimmune Disease in Canada
Managing a chronic autoimmune disease affects many areas of life — from work and relationships to mental health and daily routines. The good news is that most people with autoimmune conditions can live full and active lives with the right support and treatment.
In Canada, provincial health plans cover many essential autoimmune treatments, including specialist visits, most blood tests, and hospital care. However, some medications — particularly biologics — may not be fully covered under provincial plans. In these cases, private insurance or provincial drug programmes may help cover costs.
Support groups and patient advocacy organizations can also be valuable. Connecting with others who share your experience can reduce feelings of isolation and provide practical tips for day-to-day living. Ask your healthcare provider about community resources in your area.
When to See a Doctor
You should speak with a healthcare provider if you notice persistent or unexplained symptoms such as ongoing fatigue, joint pain, recurring rashes, or unusual muscle weakness. These symptoms alone do not confirm an autoimmune disease, but they are worth investigating.
Start by booking an appointment with your family doctor. They can review your symptoms, order initial blood tests, and refer you to a specialist if needed. If you do not have a family doctor, a walk-in clinic is a good first step. A walk-in clinic doctor can order basic tests and help guide your care.
Do not wait too long to seek help. Early diagnosis and treatment can make a significant difference in slowing disease progression and protecting your quality of life. Trust your instincts — if something feels wrong, it is always better to get it checked.
Always consult a qualified healthcare provider for a proper diagnosis and personalized treatment plan. The information in this article is for general educational purposes only and does not replace professional medical advice.
Frequently Asked Questions About Autoimmune Disease
What is an autoimmune disease in simple terms?
An autoimmune disease is a condition where your immune system mistakenly attacks your own healthy cells and tissues. Instead of protecting you from germs, it treats parts of your body as a threat. There are more than 80 known autoimmune diseases, ranging from thyroid conditions to lupus and rheumatoid arthritis.
What are the most common autoimmune diseases in Canada?
Some of the most common autoimmune diseases diagnosed in Canada include rheumatoid arthritis, type 1 diabetes, multiple sclerosis, Hashimoto’s thyroiditis, and lupus. Canada has one of the highest rates of multiple sclerosis in the world. Your family doctor can help assess your symptoms and refer you to the right specialist.
Can an autoimmune disease be cured?
Currently, most autoimmune diseases cannot be cured. However, many people successfully manage their condition with medication, lifestyle changes, and regular medical care. Treatment focuses on reducing symptoms, controlling inflammation, and preventing long-term organ damage.
What triggers an autoimmune disease flare
