Reduced FEV1

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

This is the amount of air that you can forcibly blow out in one second, measured in litres. Along with FVC it is considered one of the primary indicators of lung function.It is decreased in obstructive lung disease in proportion to severity of obstruction. It is even reduced in severe restrictive disease of lung.

Differential diagnosis

Common causes

• Emphysema

• Post intubation strictures
• Bronchiolitis

• Bronchiectasis

• Pneumonia
• Obesity

Organ system based

Cardiovascular	No underlying causes
Chemical / poisoning	No underlying causes
Dermatologic	No underlying causes
Drug Side Effect	No underlying causes
Ear Nose Throat	Glottic strictures, Laryngeal lesions, Tracheomalacia
Endocrine	Goiter
Environmental	No underlying causes
Gastroenterologic	Ascites
Genetic	Laryngomalacia, Trachea ring abnormality
Hematologic	No underlying causes
Iatrogenic	Post intubation strictures
Infectious Disease	Bronchiolitis, Bronchiolitis obliterans, Laryngotracheobronchitis, Pneumonia, Aspiration, Pulmonary larval infestation/nematodes, Pulmonary larval migrans
Musculoskeletal / Ortho	Kyphoscoliosis, Tracheobronchiopathia osteoplastica
Neurologic	No underlying causes
Nutritional / Metabolic	No underlying causes
Obstetric/Gynecologic	Pregnancy
Oncologic	Tracheal adenoma, Malignant tracheal tumor
Opthalmologic	No underlying causes
Overdose / Toxicity	No underlying causes
Psychiatric	No underlying causes
Pulmonary	Bronchiectasis, Pneumonia, Emphysema, Mounieer-Kuhn syndrome, Pulmonary alveolar proteinosis, Relapsing polychondritis
Renal / Electrolyte	No underlying causes
Rheum / Immune / Allergy	Ankylosing spondylitis, Asthma, Extrinsic/allergic asthma syndrome, Hyper-reactive airway disease, Hypersensitivity pneumonitis, Allergic tracheitis
Sexual	No underlying causes
Trauma	No underlying causes
Urologic	No underlying causes
Dental	No underlying causes
Miscellaneous	Aging, Obesity, Chronic smoking

Alphabetical order

• Aging

• Ankylosing spondylitis

• Ascites

• Asthma

• Bronchiectasis

• Bronchiolitis obliterans

• Bronchiolitis

• Chronic smoking

• Emphysema

• Extrinsic/allergic asthma syndrome

• Glottic strictures

• Goiter

• Hyper-reactive airway disease

• Hypersensitivity pneumonitis

• Kyphoscoliosis

• Laryngeal lesions

• Laryngomalacia

• Laryngotracheobronchitis

• Mounieer-Kuhn syndrome

• Obesity

• Aspiration pneumonia

• Pneumonia

• Post intubation strictures

• Pregnancy

• Pulmonary alveolar proteinosis

• Pulmonary larval infestation/nematodes

• Pulmonary larval migrans

• Relapsing polychondritis

• Trachea ring abnormality

• Tracheal adenoma

• Tracheal tumor, secondary malignant

• Tracheitis, allergic

• Tracheobronchiopathia osteoplastica

• Tracheomalacia

See also

• Spirometry

• Peak flow meter