Table of ContentsView AllTable of ContentsPurpose of TestingInterpreting ResultsWhat to ExpectRisks and Contraindications
Table of ContentsView All
View All
Table of Contents
Purpose of Testing
Interpreting Results
What to Expect
Risks and Contraindications
An expiratory reserve volume (ERV) is the amount of air that you can exhale when you push out all the air possible after your “normal” breath. This extra ERV air is a part of your totallung vital capacity. It is one of the metrics measured during lung volume testing throughspirometry, a type ofpulmonary function test.
Typically, these tests are used to evaluate lung function in diagnosing or reassessing lung disease such asasthma. ERV is among the first signs of breathing change due toobesity.Other factors, including age, gender, and even the altitude where you live, can affect ERV and related values.
This article explains how ERV and other pulmonary function metrics are measured and what they can mean.
Asthma Inhaler.Jonathan Ernst / Stringer / Getty Images
Purpose of Pulmonary Function Tests
Expiratory reserve volume is an important measurement of lung function testing when combined with other results from your pulmonary function test. These measures include:
Computed tomography(CT) scans and other imaging of the lungs cannot provide these measurements or make distinctions between diseases on the basis of how your lungs work. So spirometry and other tests are used to diagnose and distinguish between lung diseases such aschronic obstructive pulmonary disease(COPD),asthma, andpulmonary fibrosis.
What Is an Average ERV Result?The average ERV volume is about 1200 milliliters (mL) in males and 700 mL in females.
What Is an Average ERV Result?
The average ERV volume is about 1200 milliliters (mL) in males and 700 mL in females.
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Interpreting ERV and Pulmonary Test Results
ERV is not a separate test and is measured along with VC and other values.It’s added to RV to determine functional reserve capacity (FRC), the air left in the lungs after a normal, passive exhalation. The FRC is used to evaluate the elasticity of the lungs and chest wall.
Variousratiosare calculated with these values. If the ERV-to-VC ratio is high, it suggests that the lungs are stiff and unable to expand and contract properly; lung fibrosis might be the culprit. Or, if that ratio is very low, it could mean asthma-related resistance.
The results of pulmonary function testing, including ERV measurements, can contribute information used to:
The pulmonary function tests also serve to assess fitness and may be a part of any evaluation to determine a lung-related disability.
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What to Expect During the Test
For the actual test, you will sit in a chair. A nose clip will ensure that you breathe only through your mouth. You’ll be given a small hand-held device with a sterile mouthpiece that connects to a spirometer, a machine that will record the force of your breath and print out the results.
The healthcare provider will give you specific instructions about how to hold the mouthpiece and breathe into it, exhaling as instructed (often, as hard and fast as you can) after a full breath.You’ll likely be asked to do this at least three times.
Pulmonary function tests such as spirometry are very safe procedures, but some people do experience shortness of breath, lightheadedness, or coughing.
There’s a very small risk of an asthma attack for those who have asthma. There also are a handful of people for whom PFTs are contraindicated, including those who:
Pregnant people and people experiencing stomach bloating, extreme fatigue, or muscle weakness may not get accurate results from PFTs.
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Summary
Expiratory reserve volume is a pulmonary function measure that’s evaluated alongside other measures when completing spirometry and pulmonary function testing. It is generally safe, noninvasive, and can provide information about your breathing status and lung function in a way that X-rays and CT scans can’t.
Remember that ERV is just one measurement performed in a pulmonary function test that can help your healthcare provider narrow down a diagnosis of your respiratory condition. This will, in turn, help to inform an effective treatment plan.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Shah NM, Kaltsakas G.Respiratory complications of obesity: from early changes to respiratory failure.Breathe (Sheff).2023 Mar;19(1):220263. doi:10.1183/20734735.0263-2022Netzer NC, Rausch LK, Frieß M, Strohl KP, Schilz R, Decker M,et al.Expiratory peak flow and minute ventilation are significantly increased at high altitude versus simulated altitude in normobaria.Life (Basel). 2022 Feb 17;12(2):306. doi:10.3390/life12020306NIH MedlinePlus.Pulmonary function tests.American Lung Association.Lung capacity and aging.Physiopedia.Lung volumes.Douglas MM, Douglas JM. 15. In:Exploring Human Biology in the Laboratory. Morton Publishing Company; 2016:234.Johns Hopkins Medicine.Pulmonary function tests.American Academy of Family Physician.Office spirometry: Indications and interpretation.Icahn School of Medicine at Mount Sinai.Pulmonary function testing.Additional ReadingAmerican Lung Association.Lung Procedures, Tests & Treatments.Lutfi M.The Physiological Basis and Clinical Significance of Lung Volume Measurements. Multidisciplinary Respiratory Medicine. 2017;12:3.National Heart, Lung, and Blood Institute.Pulmonary Hypertension.Ponce MC, Sharma S.Pulmonary Function Tests. National Center for Biotechnology Information.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Shah NM, Kaltsakas G.Respiratory complications of obesity: from early changes to respiratory failure.Breathe (Sheff).2023 Mar;19(1):220263. doi:10.1183/20734735.0263-2022Netzer NC, Rausch LK, Frieß M, Strohl KP, Schilz R, Decker M,et al.Expiratory peak flow and minute ventilation are significantly increased at high altitude versus simulated altitude in normobaria.Life (Basel). 2022 Feb 17;12(2):306. doi:10.3390/life12020306NIH MedlinePlus.Pulmonary function tests.American Lung Association.Lung capacity and aging.Physiopedia.Lung volumes.Douglas MM, Douglas JM. 15. In:Exploring Human Biology in the Laboratory. Morton Publishing Company; 2016:234.Johns Hopkins Medicine.Pulmonary function tests.American Academy of Family Physician.Office spirometry: Indications and interpretation.Icahn School of Medicine at Mount Sinai.Pulmonary function testing.Additional ReadingAmerican Lung Association.Lung Procedures, Tests & Treatments.Lutfi M.The Physiological Basis and Clinical Significance of Lung Volume Measurements. Multidisciplinary Respiratory Medicine. 2017;12:3.National Heart, Lung, and Blood Institute.Pulmonary Hypertension.Ponce MC, Sharma S.Pulmonary Function Tests. National Center for Biotechnology Information.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Shah NM, Kaltsakas G.Respiratory complications of obesity: from early changes to respiratory failure.Breathe (Sheff).2023 Mar;19(1):220263. doi:10.1183/20734735.0263-2022Netzer NC, Rausch LK, Frieß M, Strohl KP, Schilz R, Decker M,et al.Expiratory peak flow and minute ventilation are significantly increased at high altitude versus simulated altitude in normobaria.Life (Basel). 2022 Feb 17;12(2):306. doi:10.3390/life12020306NIH MedlinePlus.Pulmonary function tests.American Lung Association.Lung capacity and aging.Physiopedia.Lung volumes.Douglas MM, Douglas JM. 15. In:Exploring Human Biology in the Laboratory. Morton Publishing Company; 2016:234.Johns Hopkins Medicine.Pulmonary function tests.American Academy of Family Physician.Office spirometry: Indications and interpretation.Icahn School of Medicine at Mount Sinai.Pulmonary function testing.
Shah NM, Kaltsakas G.Respiratory complications of obesity: from early changes to respiratory failure.Breathe (Sheff).2023 Mar;19(1):220263. doi:10.1183/20734735.0263-2022
Netzer NC, Rausch LK, Frieß M, Strohl KP, Schilz R, Decker M,et al.Expiratory peak flow and minute ventilation are significantly increased at high altitude versus simulated altitude in normobaria.Life (Basel). 2022 Feb 17;12(2):306. doi:10.3390/life12020306
NIH MedlinePlus.Pulmonary function tests.
American Lung Association.Lung capacity and aging.
Physiopedia.Lung volumes.
Douglas MM, Douglas JM. 15. In:Exploring Human Biology in the Laboratory. Morton Publishing Company; 2016:234.
Johns Hopkins Medicine.Pulmonary function tests.
American Academy of Family Physician.Office spirometry: Indications and interpretation.
Icahn School of Medicine at Mount Sinai.Pulmonary function testing.
American Lung Association.Lung Procedures, Tests & Treatments.Lutfi M.The Physiological Basis and Clinical Significance of Lung Volume Measurements. Multidisciplinary Respiratory Medicine. 2017;12:3.National Heart, Lung, and Blood Institute.Pulmonary Hypertension.Ponce MC, Sharma S.Pulmonary Function Tests. National Center for Biotechnology Information.
American Lung Association.Lung Procedures, Tests & Treatments.
Lutfi M.The Physiological Basis and Clinical Significance of Lung Volume Measurements. Multidisciplinary Respiratory Medicine. 2017;12:3.
National Heart, Lung, and Blood Institute.Pulmonary Hypertension.
Ponce MC, Sharma S.Pulmonary Function Tests. National Center for Biotechnology Information.
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