5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease

ABIM Internal Medicine Exam

Track your progress as you read

Finished sections get a check mark.

1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy

0.1 Exam Format, Question Types & the 2026 Blueprint 0.2 Eligibility, Registration, Fees & Exam-Day Logistics 0.3 Scoring, the Passing Standard & Score Reports 0.4 Building a Blueprint-Weighted Study Plan

2 Chapter 1: Cardiovascular Disease (14% of Exam)

1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection

3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)

2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia

4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)

3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV

5 Chapter 4: Infectious Disease (9% of Exam)

4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections

6 Chapter 5: Pulmonary Disease (9% of Exam)

5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule

7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)

6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease

8 Chapter 7: Hematology (6% of Exam)

7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation

9 Chapter 8: Medical Oncology (6% of Exam)

8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care

10 Chapter 9: Nephrology & Urology (6% of Exam)

9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria

11 Chapter 10: Neurology (4% of Exam)

10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders

12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)

11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health

13 Chapter 12: Dermatology (3% of Exam)

12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease

14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)

13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications

15 Chapter 14: Geriatric Syndromes (3% of Exam)

14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings

16 Chapter 15: Allergy & Immunology (2% of Exam)

15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders

17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology

16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design

18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)

17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity

19 Chapter 18: Perioperative Medicine & Medical Consultation

18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications

20 Chapter 19: Ophthalmology (1% of Exam)

19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease

21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)

20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders

5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease

Key Takeaways Explain This Topic AI

Bronchiectasis, congenital lung disease with cystic fibrosis and alpha-1 antitrypsin deficiency, and restrictive lung disease are three separate blueprint subsections.

Bronchiectasis is confirmed by high-resolution computed tomography showing airway dilation exceeding the accompanying vessel diameter.

Cystic fibrosis is now frequently diagnosed in adults with bronchiectasis, pancreatic insufficiency, sinus disease or male infertility from absent vasa deferentia.

Extrapulmonary restriction from obesity, chest wall disease or neuromuscular weakness reduces lung volumes with a preserved or elevated diffusing capacity corrected for alveolar volume.

A falling forced vital capacity measured supine identifies diaphragmatic weakness in neuromuscular disease and predicts respiratory failure.

Last updated: August 2026

1. Bronchiectasis

Bronchiectasis is permanent, abnormal dilation of the bronchi resulting from a self-perpetuating cycle of infection, inflammation and airway wall destruction. It is listed as its own blueprint subsection.

Presentation: chronic productive cough with large-volume purulent sputum , recurrent exacerbations, hemoptysis (occasionally massive from hypertrophied bronchial arteries), and crackles with occasional wheeze.

Diagnosis is radiologic. High-resolution CT shows bronchial dilation exceeding the diameter of the accompanying pulmonary artery (the signet ring sign), lack of normal distal tapering, and airway visibility within 1 cm of the pleura. Tram-track opacities may be visible on plain radiographs.

Finding the cause is the exam task

Bronchiectasis is a pattern of injury , not a diagnosis. Every case requires an etiologic workup:

Category Causes Directed testing

Post-infectious Severe pneumonia, tuberculosis , non-tuberculous mycobacteria, pertussis, measles Sputum acid-fast bacilli and culture

Genetic Cystic fibrosis , primary ciliary dyskinesia, alpha-1 antitrypsin deficiency Sweat chloride, CFTR genotyping, nasal nitric oxide

Immunodeficiency Common variable immunodeficiency , other humoral defects Quantitative immunoglobulins, vaccine response

Obstruction Foreign body, tumor, right middle lobe syndrome Bronchoscopy

Allergic Allergic bronchopulmonary aspergillosis — proximal and central bronchiectasis Total IgE, Aspergillus -specific IgE, precipitins, eosinophils

Autoimmune Rheumatoid arthritis, Sjogren syndrome, inflammatory bowel disease Serology

Two patterns worth memorizing. Upper-lobe predominant bronchiectasis suggests cystic fibrosis or allergic bronchopulmonary aspergillosis. Right middle lobe and lingular bronchiectasis with nodules in an older thin woman is the Lady Windermere syndrome of Mycobacterium avium complex infection.

Management is airway clearance (chest physiotherapy, hypertonic saline), treatment of exacerbations with antibiotics directed by prior sputum cultures, chronic macrolide therapy for frequent exacerbators after excluding non-tuberculous mycobacteria, and treatment of the underlying cause. Inhaled corticosteroids are not routine unless there is coexisting asthma or COPD.

2. Allergic Bronchopulmonary Aspergillosis

A hypersensitivity reaction to Aspergillus fumigatus colonizing the airway, occurring almost exclusively in asthma or cystic fibrosis . Suspect it in an asthmatic with recurrent infiltrates, brownish mucus plugs and worsening control despite adherence.

Diagnostic features: markedly elevated total IgE (typically above 1,000 IU/mL), positive Aspergillus skin test or specific IgE, precipitating antibodies, eosinophilia , and central (proximal) bronchiectasis — the reverse of most causes, which are distal.

Treatment is systemic corticosteroids with itraconazole as a steroid-sparing agent. This is one of the few pulmonary conditions in which a fungal organism is treated primarily with immunosuppression rather than antifungals alone.

3. Cystic Fibrosis in Adults

Autosomal recessive CFTR dysfunction. Because survival now extends well into adulthood and milder genotypes present late, cystic fibrosis is a real adult internal medicine diagnosis and is enumerated under both Pulmonary Disease and Gastroenterology.

Adult presentations to recognize:

• Bronchiectasis with chronic Pseudomonas aeruginosa or Staphylococcus aureus colonization
• Pancreatic exocrine insufficiency with steatorrhea and fat-soluble vitamin deficiency
• Cystic fibrosis-related diabetes
• Chronic rhinosinusitis with nasal polyps

Male infertility from congenital bilateral absence of the vas deferens — often the sole manifestation of a mild genotype

Distal intestinal obstruction syndrome; biliary cirrhosis

Diagnosis: sweat chloride testing is first line, supplemented by CFTR genotyping. Adults with mild variants may have intermediate sweat chloride values.

CFTR modulator therapy has transformed outcomes for patients with responsive genotypes and is now the cornerstone of care alongside airway clearance, inhaled antibiotics and pancreatic enzyme replacement.

4. Alpha-1 Antitrypsin Deficiency

Listed under congenital lung disease. Loss of antiprotease protection permits neutrophil elastase to destroy alveolar walls.

The distinguishing features versus ordinary smoking-related COPD:

• Alpha-1 antitrypsin deficiency Typical smoking-related COPD
• Emphysema distribution Basilar, panacinar Apical, centrilobular
• Age at onset Often under 45 Usually over 55
• Smoking history May be minimal or absent Substantial
• Extrapulmonary Liver disease , panniculitis None

Current guidance recommends testing every patient diagnosed with COPD at least once , using a serum alpha-1 antitrypsin level with phenotyping or genotyping if low. Smoking cessation is the single most important intervention, because smoking accelerates decline dramatically in these patients. Intravenous augmentation therapy is available for those with severe deficiency and established emphysema; it does not treat the liver disease.

5. Restrictive Lung Disease Other Than Interstitial and Pleural Disease

A named blueprint subsection listing pulmonary complications of obesity, chest wall disorders, neuromuscular disorders and undifferentiated restrictive disease. These are extrapulmonary causes of restriction — the lung parenchyma itself is normal.

Reading the pulmonary function pattern

• Obstruction Parenchymal restriction Extrapulmonary restriction
• FEV1/FVC ratio Reduced Normal or increased Normal or increased
• Total lung capacity Normal or increased Reduced Reduced
• Residual volume Increased Reduced Variable — increased in neuromuscular weakness
• DLCO Reduced in emphysema Reduced Normal or increased
• DLCO/VA Reduced in emphysema Reduced Normal or increased

The diffusing capacity is the discriminator. Parenchymal disease damages the alveolar-capillary membrane and lowers DLCO. Extrapulmonary restriction merely compresses a normal lung, so DLCO corrected for alveolar volume is preserved or even elevated . A patient with reduced lung volumes and a normal DLCO/VA has a chest wall, neuromuscular or obesity problem — not interstitial lung disease.

Neuromuscular weakness

The highest-yield bedside test is spirometry performed supine as well as upright . Diaphragmatic weakness causes the forced vital capacity to fall by more than 10 to 20% on lying flat , because abdominal contents are no longer opposed by gravity. Maximal inspiratory and expiratory pressures quantify the deficit.

This matters clinically in amyotrophic lateral sclerosis, Guillain-Barre syndrome, myasthenia gravis and muscular dystrophy . In acute neuromuscular respiratory failure, arterial blood gases are a late and misleading indicator — carbon dioxide retention appears only after substantial reserve is exhausted. Serial vital capacity and negative inspiratory force identify the patient who needs intubation before decompensation.

Obesity and the chest wall

Obesity reduces functional residual capacity and expiratory reserve volume with a relatively preserved total lung capacity until it is severe. Kyphoscoliosis produces restriction proportional to the Cobb angle and can cause chronic hypercapnia and cor pulmonale. Ankylosing spondylitis fuses the costovertebral joints, producing chest wall restriction with a characteristically preserved or increased functional residual capacity because the chest is fixed in inspiration.