Autoimmune Disease
When the immune system attacks the body's own tissues
Quick Facts
- Type: Immune system disorder
- Examples: Lupus, rheumatoid arthritis, type 1 diabetes
- Common pattern: Flares and periods of remission
- More common in: Women
Overview
An autoimmune disease occurs when the immune system, which normally defends the body against germs, mistakenly identifies the body's own healthy cells as a threat and attacks them. This misdirected immune response causes inflammation and can damage specific organs or affect the body more widely. There are more than 80 recognized autoimmune diseases.
Some autoimmune diseases target a single organ, such as the thyroid in Hashimoto's thyroiditis or the insulin-producing cells in type 1 diabetes. Others, like lupus, can affect many parts of the body at once. Most autoimmune diseases are long-term conditions that tend to come and go in flares, and while they cannot usually be cured, they can often be managed effectively.
Symptoms
Symptoms vary widely depending on which disease and which tissues are affected, but some general features are common across many autoimmune conditions:
- Fatigue, sometimes severe
- Joint pain, stiffness, or swelling
- Recurrent low-grade fevers
- Skin rashes
- Muscle aches
- Numbness or tingling in the hands and feet
- Hair loss
- Digestive problems
Many autoimmune diseases follow a pattern of flares, when symptoms worsen, and remissions, when they ease or disappear. Because symptoms can be vague and overlap with other conditions, diagnosis can take time.
Causes
The exact reasons the immune system turns against the body are not fully understood, and most autoimmune diseases likely result from a mix of factors:
- Genetics: A family tendency toward autoimmune conditions, though specific diseases are not always inherited directly.
- Environmental triggers: Infections, certain medications, smoking, and exposures that may set off an abnormal immune response in susceptible people.
- Hormones: Many autoimmune diseases are more common in women and may be influenced by hormonal factors.
In most cases there is no single identifiable cause, and the condition develops from this combination of inherited and environmental influences.
Risk Factors
- Being female, as many autoimmune diseases are more common in women
- A family history of autoimmune conditions
- Certain infections that may trigger the immune system
- Smoking
- Already having one autoimmune disease, which raises the chance of developing another
- Certain medications and environmental exposures
Diagnosis
Because symptoms can be nonspecific, diagnosis often involves several steps and may take time:
- Medical history and examination: Reviewing symptoms, their pattern, and family history.
- Blood tests: Tests for inflammation and for specific antibodies, such as antinuclear antibodies, that point toward particular autoimmune diseases.
- Imaging: X-rays, ultrasound, or other scans to assess affected joints or organs.
- Biopsy: Sometimes a tissue sample is examined to confirm the diagnosis.
No single test diagnoses all autoimmune diseases, so doctors combine results to reach a conclusion.
Treatment
Treatment aims to control the overactive immune response, reduce inflammation, relieve symptoms, and protect affected organs. Care is tailored to the specific disease.
- Anti-inflammatory medicines: To ease pain and swelling.
- Immune-suppressing medications: Including corticosteroids and other drugs that dampen the immune attack.
- Targeted biologic therapies: Medicines that block specific parts of the immune response in certain diseases.
- Replacement therapy: Such as insulin in type 1 diabetes or thyroid hormone in an underactive thyroid.
- Lifestyle support: Balanced nutrition, regular activity as tolerated, rest, and avoiding smoking.
Ongoing follow-up helps adjust treatment, manage flares, and monitor for side effects.
When to See a Doctor
See a doctor if you have persistent or unexplained symptoms such as ongoing fatigue, joint pain and swelling, recurring rashes, or repeated low-grade fevers, especially if they come and go. An early evaluation can help identify the cause.
Seek prompt or emergency care for:
- Sudden severe shortness of breath or chest pain
- Signs of a severe flare affecting the kidneys, heart, lungs, or brain
- High fever with a known autoimmune condition, which may signal infection
- New weakness, confusion, or vision changes
Frequently Asked Questions
What causes autoimmune disease?
The exact cause is usually unknown, but autoimmune diseases tend to result from a combination of genetic susceptibility and environmental triggers such as infections, certain medications, or smoking. Hormonal factors may also play a role, since many of these conditions are more common in women.
Are autoimmune diseases curable?
Most autoimmune diseases cannot be cured, but they can often be well managed. Treatments that calm the immune system and reduce inflammation can control symptoms, prevent flares, and protect affected organs, allowing many people to live full lives.
Why are autoimmune diseases hard to diagnose?
Their symptoms are often vague, fluctuating, and overlap with many other conditions, and no single test identifies all of them. Doctors usually combine a medical history, examination, blood tests for specific antibodies, and sometimes imaging or a biopsy to reach a diagnosis.
Can you have more than one autoimmune disease?
Yes. Having one autoimmune disease increases the chance of developing another, and some tend to occur together. People with an established autoimmune condition should mention new persistent symptoms to their doctor.
What is an autoimmune flare?
A flare is a period when the disease becomes more active and symptoms worsen, sometimes followed by remission when they ease. Identifying triggers, taking medications as prescribed, and regular follow-up can help reduce the frequency and severity of flares.
References
- National Institute of Allergy and Infectious Diseases (NIAID). Autoimmune Diseases.
- MedlinePlus, U.S. National Library of Medicine. Autoimmune disorders.
- Office on Women's Health, U.S. Department of Health and Human Services. Autoimmune diseases.
- National Institutes of Health (NIH). Understanding Autoimmune Diseases.