What is Pulmonary Function Testing?

Pul­monary func­tion tests (PFTs) are a series of non-inva­sive diag­nos­tic tests that mea­sure how well your lungs work and can be used to help diag­nose cer­tain lung dis­or­ders. Pul­monary func­tion tests’ is an inclu­sive term that refers to many dif­fer­ent pro­ce­dures that mea­sure how your lungs work in dif­fer­ent ways. Specif­i­cal­ly these tests mea­sure how well you are able to breathe and how well your lungs are able to sup­ply oxy­gen to your body by mea­sur­ing your lung vol­umes, capac­i­ties, rates of flow and gas exchange.

Rea­son for Testing

Gen­er­al­ly pul­monary func­tion test­ing is ordered by your physi­cian if you are hav­ing symp­toms of lung prob­lems, as part of a rou­tine phys­i­cal or to assess how well your lungs work pri­or to under­go­ing surgery. If you have already been diag­nosed with a con­di­tion that affects your lungs, these tests may be ordered to deter­mine if the con­di­tion is pro­gress­ing or to assess how your lungs are respond­ing to treatment.

Pul­monary func­tion tests can help diag­nose or man­age the fol­low­ing conditions:

  • Asth­ma
  • Aller­gies
  • Chron­ic bronchitis
  • Res­pi­ra­to­ry infections
  • Emphy­se­ma
  • Lung fibro­sis
  • Bronchiec­ta­sis
  • Chron­ic obstruc­tive pul­monary dis­ease (COPD)
  • Asbesto­sis
  • Sar­coido­sis
  • Scle­ro­der­ma
  • Lung can­cer
  • Res­pi­ra­to­ry impair­ments that may com­pli­cate sleep apnea

How to Prepare

Pri­or to your pul­monary func­tion test:

  • On the day of your test, refrain from eat­ing a heavy meal, as this restricts your breath­ing and air­flow and avoid caf­feinat­ed bev­er­ages. Wear loose fit­ting cloth­ing so that your breath­ing isn’t restricted.
  • 12 hours pri­or to test­ing, stop tak­ing long act­ing drugs (Spiri­va, Advair, Foradil, Per­formist, Sym­bi­cort, Serevent, Brovana)
  • 6 hours pri­or to test­ing, stop exercising
  • 4 hours pri­or to test­ing, stop tak­ing short act­ing drugs (Albuterol, Xopenex, Atro­vent, Combivent)
  • 1 hour before your test stop smok­ing, and refrain from smok­ing through the dura­tion of the test

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