Autoimmune Conditions: Symptoms, Causes & Treatment

🩺 Medically reviewed by the Health Decoded Guide Editorial Team • Last reviewed: August 2026

Browse autoimmune conditions below.

🛡️ Autoimmune Disease Basics

• What Is an Autoimmune Disease?
• How the Immune System Works
• Why Does the Immune System Attack the Body?
• What Causes Autoimmune Diseases?
• Who Is More Likely to Develop an Autoimmune Disease?
• Autoimmune Disease Symptoms
• Autoimmune Disease Flare-Ups
• Can You Have More Than One Autoimmune Disease?

🦴 Joint & Connective Tissue Autoimmune Conditions

• Rheumatoid Arthritis
• Systemic Lupus Erythematosus (SLE)
• Ankylosing Spondylitis
• Psoriatic Arthritis
• Sjögren's Syndrome
• Systemic Sclerosis (Scleroderma)
• Polymyalgia Rheumatica
• Polymyositis
• Dermatomyositis

🦋 Thyroid & Hormonal Autoimmune Conditions

• Hashimoto's Thyroiditis
• Graves' Disease
• Type 1 Diabetes
• Addison's Disease

🧴 Skin & Hair Autoimmune Conditions

• Psoriasis
• Vitiligo
• Alopecia Areata
• Pemphigus
• Bullous Pemphigoid

🥣 Digestive System Autoimmune Conditions

• Celiac Disease
• Crohn's Disease
• Ulcerative Colitis
• Autoimmune Hepatitis
• Primary Biliary Cholangitis

🧠 Brain, Nerve & Muscle Autoimmune Conditions

• Multiple Sclerosis (MS)
• Myasthenia Gravis
• Guillain-Barré Syndrome
• Autoimmune Encephalitis

🩸 Blood & Blood Vessel Autoimmune Conditions

• Autoimmune Haemolytic Anaemia
• Immune Thrombocytopenia (ITP)
• Antiphospholipid Syndrome
• Vasculitis

🔬 Diagnosis & Testing

• How Autoimmune Diseases Are Diagnosed
• ANA Test Explained
• ESR and CRP Explained
• Autoantibody Tests Explained
• Why Autoimmune Diseases Can Take Time to Diagnose
• When You May Be Referred to a Rheumatologist

💊 Treatment & Management

• Autoimmune Disease Treatment Explained
• Steroids (Corticosteroids) Explained
• Immunosuppressant Medicines Explained
• Biologic Medicines Explained
• Managing an Autoimmune Flare-Up
• Exercise and Autoimmune Conditions
• Living With an Autoimmune Disease

🚨 When to Seek Medical Care

• Persistent Unexplained Joint Pain or Swelling
• Recurrent or Unexplained Rashes
• Persistent Unexplained Fatigue
• New Muscle Weakness
• New Numbness or Neurological Symptoms
• Symptoms Affecting Several Parts of the Body
• When Autoimmune Symptoms Need Urgent Medical Attention