How Long Does It Take to Get Pulmonary Function Test Results?

Most pulmonary function test results are technically available within minutes of completing the test, but the fully interpreted report from a physician typically reaches you within a few days to two weeks, depending on where you were tested and how your healthcare system delivers results. The gap between the raw numbers and the doctor’s interpretation is where almost all the waiting happens. That distinction matters, because the numbers alone can look alarming or reassuring in ways that only make sense once a specialist has compared them to the right reference values for your age, height, sex, and ethnicity.

What Happens During the Test Itself

Pulmonary function tests encompass several different procedures, and the type you undergo affects both how long the appointment lasts and how quickly usable data emerges. The most common test, spirometry, involves blowing into a mouthpiece as hard and as long as you can. The machine records your airflow in real time and displays numerical results on a screen within seconds of each effort. A technician usually asks you to repeat the maneuver at least three times to ensure the readings are reproducible, so the whole spirometry portion often wraps up in about 15 to 20 minutes.

If your doctor has ordered bronchodilator reversibility testing, the appointment gets longer. You perform spirometry, then inhale a bronchodilator medication, wait for it to take effect, and blow again. A study in a pediatric pulmonary clinic found that extending the wait after bronchodilator administration from roughly 6.5 minutes to about 16 minutes added around nine minutes to overall clinic visit times, pushing average appointments from about 83 minutes to about 92 minutes.¹ That extra time matters clinically because it catches more cases of genuine airway reversibility, but it does mean you’ll be in the lab longer.

Full pulmonary function testing can also include lung volume measurements (plethysmography, where you sit in a sealed booth) and a diffusing capacity test (DLCO), which measures how efficiently your lungs transfer gas into your bloodstream. A complete panel with all three components can take 45 minutes to over an hour, though each individual measurement generates data almost instantly on the equipment.

Why the Numbers Come Fast but the Report Takes Longer

Here is the part that confuses a lot of people: the raw numbers exist the moment you finish blowing. The spirometer has already calculated your forced expiratory volume (how much air you can push out in one second), your total forced vital capacity, and the ratio between them. The DLCO machine has already computed your gas transfer value. A technician can see all of these on screen before you leave the room. In many hospital-based pulmonary function labs, the technician will even tell you informally whether your effort looked “good” or whether a value seems unusually low.

But those numbers mean very little without context. Interpretation requires comparing your values to predicted norms, selecting the appropriate reference equations, and deciding whether any abnormality is obstructive, restrictive, or mixed. That interpretation is a physician’s job, and it involves reviewing the quality of each maneuver, checking that the results are internally consistent, and correlating them with your symptoms and medical history. This step can happen the same day if a pulmonologist is on-site and reviews tests in real time. More commonly, tests are batched and reviewed later, adding one to several business days.

The setting matters enormously. In a pulmonologist’s office where the doctor ordered the test and the lab is down the hall, you may get preliminary results discussed during the same visit. In a hospital outpatient lab where the ordering physician is elsewhere, the report has to be finalized, signed, and transmitted back to your doctor, who then contacts you. That chain can take anywhere from two days to two weeks, with most patients falling somewhere in the three-to-seven-day range.

Factors That Stretch the Timeline

Several practical realities push turnaround times toward the longer end of that window. Understanding them can help you set realistic expectations and know when it’s worth calling to ask.

Staffing and volume: High-volume labs process dozens of patients daily. If the interpreting physician covers multiple sites or only reviews PFTs on certain days, reports queue up. Academic medical centers tend to have faster interpretation because pulmonologists are on-site, but they also see more patients.
Test complexity: A simple pre-employment spirometry screening can be interpreted in minutes. A full panel with pre- and post-bronchodilator spirometry, lung volumes, and DLCO requires more careful review, especially if any values are borderline.
Referring physician review: Even after the pulmonary function lab finalizes its report, your primary care doctor or referring specialist needs to review it and decide how to communicate the findings to you. Some offices call within a day of receiving the report; others wait until your next scheduled appointment unless something is urgently abnormal.
Electronic health record routing: In systems where the lab and the ordering physician share the same electronic health record, the signed report appears almost immediately once finalized. When separate systems are involved, faxing or manual upload can add days.
Weekends and holidays: Tests performed late in the week often aren’t interpreted until the following Monday or Tuesday. If you have flexibility in scheduling, a Monday or Tuesday appointment tends to produce faster results.

None of these delays reflects a problem with your test or your health. They are logistical, and they are the same delays that affect most diagnostic tests in most healthcare systems.

Patient Portals and Immediate Access to Raw Data

If your healthcare system uses an online patient portal, you may see your pulmonary function test numbers before any physician has reviewed them. Many hospitals now release lab and diagnostic results to patient portals automatically, sometimes within hours of the test. This can be a double-edged sword. You might log in and see a list of values with flags like “below normal” next to them, without any narrative interpretation explaining what those flags mean in your clinical context.

Seeing flagged results before a doctor has explained them can generate unnecessary anxiety. A value that’s technically below a statistical cutoff might be clinically insignificant for you, or it might reflect a known condition that your doctor is already managing. Conversely, some patients find it empowering to see their numbers early and come to the follow-up appointment with informed questions. If you’re someone who tends to worry, it can help to know that the raw portal release is not the same thing as the interpreted report. Wait for the physician’s summary before drawing conclusions.

The Psychological Weight of Waiting

The period between completing a medical test and receiving results is genuinely stressful for many people, and research confirms that this stress has measurable cognitive effects. A study on anticipating medical test results found that people waiting for imminent results experienced increased cognitive distraction, which lowered their ability to process and recall information about the test and the condition being evaluated.² In practical terms, this means that if your doctor tries to explain what the test measures or what different outcomes might mean right before giving you results, you’re less likely to absorb it.

This finding has implications for how you might prepare. If you know a follow-up call or appointment is coming, write down your questions beforehand. Ask the doctor to repeat the key finding in plain language. Request a printed or emailed copy of the report summary so you can review it later when you’re calmer. The distraction effect is not a personal failing; it’s a well-documented response to the uncertainty of waiting for health information.

Making Sense of What the Report Says

When results do arrive, they typically include a set of measured values, each expressed as a percentage of what is predicted for someone of your age, height, sex, and ethnic background. The two values most people focus on are the forced expiratory volume in one second (FEV1), which reflects how quickly you can push air out of your lungs, and the forced vital capacity (FVC), which reflects total lung volume during a forced exhalation. The ratio between those two numbers is a key indicator of obstructive conditions like asthma and chronic obstructive pulmonary disease.

How that ratio is interpreted matters more than most patients realize. Older guidelines used a fixed cutoff of 0.70 to define obstruction, but research across large population surveys has shown that this approach misclassifies a substantial number of people, especially older adults whose ratio naturally declines with age and younger adults in whom a slightly low ratio may be flagged unnecessarily. Using the statistically derived lower limit of normal for each individual reduces these misclassifications.³ If your report uses the fixed 0.70 cutoff and you are over 60 or under 30, it may be worth asking your doctor whether the lower limit of normal method changes the interpretation.

If your test included a DLCO measurement, that value carries important diagnostic weight. DLCO reflects how well oxygen moves from your lungs into your blood, and it helps distinguish between different causes of abnormal spirometry. In smokers with airway obstruction, a low DLCO suggests emphysema, while a normal DLCO makes chronic asthma more likely. In patients whose spirometry suggests restriction, a low DLCO points toward interstitial lung disease, while a normal value suggests the restriction is coming from the chest wall rather than the lung tissue itself. A DLCO below about 40 percent of predicted is associated with increased risk of serious complications.⁴

When Results Are Abnormal

An abnormal pulmonary function test does not necessarily mean a new diagnosis. PFT results are snapshots that can be influenced by your effort during the test, whether you used your inhalers that morning, recent respiratory infections, and even posture. If you didn’t perform the forced expiration with maximal effort, or if you coughed partway through the maneuver, the technician ideally would have noted it and asked you to repeat, but suboptimal efforts occasionally make it into the final data.

Mildly abnormal results in someone with no symptoms may prompt your doctor to schedule a repeat test rather than jump to a diagnosis. Clearly abnormal results, especially when they align with symptoms like shortness of breath, chronic cough, or exercise intolerance, usually lead to further evaluation, which might include imaging, blood work, or a referral to a pulmonologist if you’re not already seeing one. If your results come back with a severity classification like “moderate obstruction” or “severe restriction,” your doctor will want to correlate that with your clinical picture before deciding on treatment changes.

One thing worth knowing: if your initial test was done without bronchodilator reversibility testing and showed obstruction, your doctor will likely want to repeat it with a bronchodilator to determine whether the obstruction is reversible (suggesting asthma) or fixed (suggesting COPD or another structural problem). This means another appointment, another wait for results, and another round of interpretation. The timeline for the full diagnostic picture can stretch to several weeks when multiple rounds of testing are needed.

How to Speed Things Up

You have more control over the timeline than you might think. A few practical steps can shave days off your wait.

First, ask at the time of the test when you should expect results and how they’ll be delivered. Some labs will tell you that results are typically finalized within 48 hours; others will say a week. Knowing the expected window saves you from calling too early and getting a vague “not ready yet,” or waiting passively when a result should have arrived days ago.

Second, if your healthcare system has a patient portal, register for it before your test. Results that would otherwise require a phone call or a mailed letter can appear electronically hours after the interpreting physician signs off. Even if you prefer to wait for the doctor’s explanation, having portal access means you’ll know the moment the report is finalized.

Third, schedule your test early in the week and early in the day when possible. Labs that batch interpretations daily will process your test sooner if it arrives in the morning queue on a Monday rather than the Friday afternoon pile.

Finally, if more than two weeks have passed without hearing anything, call. Reports occasionally get lost in the system, especially when the ordering physician and the testing facility are in different health networks. A quick phone call to either the lab or your doctor’s office can dislodge a stalled result.

Remote Monitoring and Emerging Technology

The traditional model of traveling to a pulmonary function lab, performing the test, and then waiting days for a report may not be the only option for much longer. Researchers have demonstrated real-time pulmonary function test monitoring through cloud-based platforms using a smartphone’s built-in microphone. In a proof-of-concept system, patients performed spirometry-like maneuvers at home, and the key ratio of FEV1 to FVC was transmitted to a physician who could monitor it remotely in real time.⁵

This technology is still in its early stages and not yet a replacement for laboratory-grade spirometry, which uses calibrated equipment and trained technicians to ensure quality. But for patients with chronic conditions like COPD or asthma who need frequent monitoring, the appeal is obvious: test yourself at home, see the results instantly, and have your doctor alerted automatically if values drop below a threshold. The “waiting for results” problem essentially disappears when the test and the result happen in the same moment on the same device.

Portable handheld spirometers are already commercially available and used in some primary care offices. These devices produce results immediately on a connected tablet or computer, allowing the doctor to discuss findings with you in real time. If your doctor uses one of these during an office visit, you may walk out with both the numbers and the interpretation the same day. The trade-off is that handheld devices generally cannot measure lung volumes or DLCO, so they work for screening and monitoring but not for a comprehensive evaluation.

Children and Pulmonary Function Testing

If your child is getting pulmonary function tests, expect the appointment itself to take longer. Children, especially those under about eight years old, often need extra coaching to perform the forced expiration correctly. The technician may spend more time demonstrating the technique, offering encouragement, and repeating maneuvers until acceptable quality is achieved. Some pediatric labs use animated computer games that respond to the child’s airflow to make the experience feel less intimidating.

The turnaround time for results is generally similar to adults, but pediatric interpretation carries its own challenges. Reference values for children are more variable because lung function changes rapidly with growth. A value that looks slightly low might be perfectly normal for a child’s height and developmental stage, or it might signal early asthma. Pediatric pulmonologists tend to be cautious about over-interpreting single test results in growing children, which sometimes means your child’s doctor will want serial tests over months before drawing firm conclusions. Each round involves its own waiting period, so the process can feel slower even when the lab is running efficiently.

The bronchodilator reversibility testing mentioned earlier is commonly performed in children suspected of having asthma. The study that examined extended wait times after bronchodilator administration was conducted specifically in a pediatric pulmonary clinic, and it found that giving the medication more time to work improved the identification of reversible airway obstruction.¹ If your child’s test includes this step, the longer wait during the appointment is by design and reflects better clinical practice, not a problem with the process.