Autoimmune Disease
When the immune system mistakenly attacks the body's own tissues
Quick Facts
- Type: Immune-system disorders
- Mechanism: Immune attack on healthy tissue
- Number known: More than 80 different diseases
- More common in: Women, often during the working years
Overview
The immune system normally defends the body against germs while leaving its own tissues alone. In an autoimmune disease, this self-tolerance breaks down and the immune system mistakenly targets healthy cells, organs, or systems. The result is inflammation and, over time, tissue damage in the affected area.
There are more than 80 recognized autoimmune diseases. Some affect a single organ, such as the thyroid in Hashimoto's disease, while others affect many parts of the body, such as lupus. "Autoimmune" is therefore an umbrella term rather than a single illness, and the symptoms, course, and treatment vary widely depending on which condition a person has.
Symptoms
Symptoms depend on which tissues are involved, but several general features are common across many autoimmune diseases:
- Fatigue and a general feeling of being unwell
- Joint pain, swelling, or morning stiffness
- Recurrent low-grade fevers
- Skin rashes or changes
- Symptoms that come and go in flares, with periods of improvement (remission) in between
Organ-specific diseases cause their own symptoms, such as digestive problems in inflammatory bowel disease or changes in energy and weight in thyroid disorders. Because early symptoms are often vague and overlap with other illnesses, autoimmune diseases can take time to diagnose.
Causes
The exact cause of most autoimmune diseases is not fully understood. They are thought to result from a combination of factors that cause the immune system to lose tolerance for the body's own tissues:
- Genetics: certain inherited gene patterns increase susceptibility, which is why these conditions can run in families.
- Environmental triggers: infections, certain medications, or other exposures may set off an abnormal immune response in susceptible people.
- Hormonal factors: many autoimmune diseases are more common in women, suggesting hormones play a role.
In most cases, no single cause can be identified, and the disease likely develops from several factors acting together.
Risk Factors
- Being female, as many autoimmune diseases are more common in women
- A family history of autoimmune disease
- Having one autoimmune condition, which raises the chance of developing another
- Certain infections or environmental exposures
- Smoking, which is linked to several autoimmune conditions
Diagnosis
Diagnosing an autoimmune disease often takes several steps, because symptoms can be nonspecific and overlap with other conditions.
- History and examination: identifying the pattern of symptoms and affected organs.
- Blood tests: markers of inflammation (such as ESR and CRP) and tests for specific autoantibodies that the immune system makes against the body's own tissues.
- Organ-specific tests: imaging, biopsies, or function tests tailored to the suspected condition.
No single test confirms most autoimmune diseases; diagnosis usually combines the clinical picture with laboratory and other findings, and sometimes requires evaluation by a specialist such as a rheumatologist.
Treatment
Most autoimmune diseases cannot be cured, but treatment can control inflammation, ease symptoms, and protect organs. Plans are tailored to the specific condition.
- Anti-inflammatory and immune-modifying medicines: such as corticosteroids and disease-modifying drugs to calm the immune attack.
- Biologic therapies: targeted medicines that block specific inflammatory signals in many autoimmune diseases.
- Replacement therapy: when a gland is damaged, such as thyroid hormone in hypothyroidism or insulin in type 1 diabetes.
- Symptom management: pain relief, physical therapy, and lifestyle support.
Because immune-suppressing treatments can raise infection risk, ongoing monitoring with the care team is important.
Prevention
Most autoimmune diseases cannot be prevented because their causes are not fully known. General measures may support immune and overall health and help manage existing disease:
- Avoid smoking, which is linked to several autoimmune conditions
- Stay physically active and maintain a balanced diet
- Manage stress, which can trigger flares in some people
- Keep up with recommended vaccinations, as advised by your doctor
- Attend regular check-ups so any condition is caught and treated early
When to See a Doctor
See a doctor if you have persistent, unexplained symptoms such as ongoing fatigue, joint pain and swelling, recurrent rashes, or repeated low-grade fevers, especially if they come and go in flares. Seek prompt care if you have:
- A severe flare with high fever, intense pain, or rapidly worsening symptoms
- Signs of a serious infection while on immune-suppressing medication
- New chest pain, shortness of breath, severe abdominal pain, or neurological changes
Early evaluation helps confirm the diagnosis and start treatment before lasting damage occurs.
Frequently Asked Questions
What does autoimmune mean?
Autoimmune means the immune system, which normally fights germs, mistakenly attacks the body's own healthy tissues. This causes inflammation and damage in the affected organ or system, and it is the basis of more than 80 different diseases.
Can autoimmune diseases be cured?
Most cannot be cured, but many can be well controlled. Treatments reduce inflammation, ease symptoms, and protect organs, and many people have long periods of remission with proper management.
Why are autoimmune diseases more common in women?
Many autoimmune diseases occur more often in women, and hormones are believed to play a role along with genetic and immune factors. The exact reasons are still being studied.
Are autoimmune diseases inherited?
You do not inherit a specific autoimmune disease directly, but you can inherit a tendency toward autoimmunity. This is why these conditions often run in families and why having one autoimmune disease raises the chance of developing another.
Do autoimmune diseases come and go?
Many follow a pattern of flares, when symptoms worsen, and remissions, when they improve. Identifying and managing triggers and staying on prescribed treatment can help reduce the frequency and severity of flares.
References
- National Institute of Allergy and Infectious Diseases (NIAID). Autoimmune Diseases.
- Office on Women's Health, U.S. Department of Health and Human Services. Autoimmune diseases.
- MedlinePlus, U.S. National Library of Medicine. Autoimmune disorders.
- Mayo Clinic. Immune system and disorders.