How to Prepare for a Spirometry Procedure

Spirometry is the rare medical test where the main ingredient is… your best “huff-and-puff” effort. It’s quick, common, and surprisingly useful for diagnosing and monitoring lung conditions like asthma and COPD. But here’s the twist: how you prepare can affect how accurate your results are. That matters because spirometry numbers can influence everything from your diagnosis to your medication plan.

This guide walks you through what to do (and what not to do) before your spirometry procedure, what happens during the test, and how to set yourself up for results you and your clinician can actually trustwithout turning your morning into a dramatic pre-test ritual.

What Is Spirometry (and Why Preparation Matters)?

Spirometry is a pulmonary function test that measures how much air you can blow out and how fast you can blow it out. Two key numbers you may hear about are:

• FVC (Forced Vital Capacity): the total amount of air you can exhale forcefully after a full inhale.
• FEV1 (Forced Expiratory Volume in 1 second): how much air you can blow out in the first second.

These values help your healthcare provider spot patterns consistent with airway narrowing (obstructive disease) or reduced lung volume (restrictive issues). Preparation matters because things like a heavy meal, recent smoking, intense exercise, or certain inhalers can temporarily change your breathing performancemaking the test look better or worse than your “real-life baseline.”

Before You Schedule: Smart Questions to Ask (So You Don’t Guess)

Spirometry instructions can vary by clinic and by the reason you’re testing. A diagnostic spirometry (to figure out what’s going on) may have different medication rules than spirometry used for monitoring a known condition. Before your appointment, call or message the clinic and ask:

• Should I stop any inhalers or breathing medications? If yes, which ones and how many hours before?
• Can I use my rescue inhaler if I feel short of breath? (Usually yes for safetyjust tell the lab you used it.)
• Should I avoid caffeine, smoking/vaping, alcohol, or exercise? And for how long?
• Will you do a bronchodilator (pre- and post-inhaler) test? That can change pre-test medication instructions.
• How long should I expect to be there? Basic spirometry is short, but some visits include extra breathing tests.

Pro tip: Ask for the instructions in writing (portal message, PDF, or email). Your future selfstaring at a lattewill appreciate it.

How to Prepare the Day Before Spirometry

1) Make a medication list (and bring it)

Write down all medicines you take, including inhalers, nebulizers, allergy meds, and any over-the-counter products. If the lab asks what you took and when, you’ll have answers instead of the classic “Ummm… blue one?” moment.

2) If you’re told to withhold inhalers, set a reminder

Many clinics may ask you to temporarily stop certain bronchodilators before testing, because they can open airways and change results. Do not stop anything unless your clinician or the testing lab tells you to. If you’re instructed to hold a medication, set an alarm so you don’t accidentally take it on autopilot.

3) Skip late-night “lung challenges”

No, you don’t need to “train” for spirometry. But you can avoid things that irritate airways or interfere with sleeplike smoke exposure, heavy drinking, or strong fumesso you’re not wheezy and miserable the next day.

4) If you’re sick, call the lab

A respiratory infection (with fever, chest congestion, or severe cough) can affect results and make the test harder to perform. Many clinics would rather reschedule than measure “what your lungs can do while you’re battling a germ invasion.” If you feel unwell, contact the testing site for guidance.

How to Prepare the Day of Spirometry

1) Wear loose, comfortable clothing

Choose clothes that don’t squeeze your chest or abdomen. Spirometry requires a deep inhale and a strong exhaletight clothing can physically limit expansion and make the test harder than it needs to be.

2) Avoid a large meal right before the test

A big meal can leave you feeling bloated, and a full stomach can make deep breathing uncomfortable. Many patient instructions recommend avoiding a heavy meal within about 2 hours of testing (some labs use slightly different timing). If you’re hungry, a light snack is usually easier on your breathing mechanics than a breakfast that could feed a small football team.

3) Don’t smoke or vape before spirometry

Smoking (and vaping) can irritate airways and change lung function measurements. Clinics commonly ask patients to avoid smoking for a window of time before testingsometimes at least an hour, and sometimes longer depending on the lab. Follow the instructions you were given, even if it means your nicotine cravings have to attend the appointment silently.

4) Avoid alcohol before your test

Some pulmonary testing instructions recommend avoiding alcohol for several hours beforehand because it can affect breathing and effort. When in doubt, skip alcohol the day of testing. Spirometry is a performance testsave the “nightcap” for a night that doesn’t require blowing like your lungs are trying to launch a rocket.

5) Hold off on heavy exercise right before spirometry

Strenuous exercise can temporarily change your breathing pattern and airway tone. Many instructions recommend avoiding heavy exercise for at least 30 minutes before testing (and sometimes longer). A calm walk is usually fine, but a sprint to the clinic parking lot is not the ideal warm-up.

6) Ask about caffeine (don’t assume)

Some lung function testing instructions suggest avoiding caffeinated foods and drinks for a period beforehand, while others don’t emphasize it. Because guidance can differ, follow your lab’s instructions. If you weren’t told anything about caffeine, askespecially if your morning routine is “coffee first, oxygen second.”

7) Arrive early and use the restroom

Arrive a bit early for check-in. And yes, use the restroom before testing. Spirometry involves repeated forceful exhalationsyour body may interpret that as “surprise core workout.” Better safe than sorry.

What Happens During the Spirometry Procedure?

Spirometry is usually done seated. You’ll breathe through a mouthpiece connected to the spirometer, and you may wear a soft nose clip to prevent air from escaping through your nose. A respiratory therapist or technician will coach you through the steps.

The basic flow (the “blow into the tube” version)

1. You’ll take normal breaths to get comfortable with the mouthpiece.
2. You’ll inhale as deeply as possiblethink “fill the lungs to the top.”
3. You’ll blast the air out hard and fast, then keep exhaling until the technician tells you to stop (often several seconds).
4. You’ll repeat the maneuver multiple times to make sure results are consistent and usable.

This repetition is normal. It’s not that you’re doing it “wrong”it’s that reliable spirometry requires multiple good efforts. You’ll often hear lots of enthusiastic coaching like “Keep going! Keep going! Keep going!” which can feel like a strange mix of medical testing and a very intense pep rally.

Sometimes there’s a bronchodilator step

In some cases, spirometry is done before and after you inhale a bronchodilator medication. This helps show whether airway narrowing improves with medicationuseful for diagnosing or assessing conditions like asthma and COPD. If your appointment includes this, you may wait a short period after using the bronchodilator and then repeat the test.

How to Get the Most Accurate Spirometry Results

1) Focus on a tight seal

Seal your lips firmly around the mouthpiece. Air leaks can make your numbers look lower than they should.

2) Don’t “pace yourself”

The exhale needs to start strong and fast. People sometimes ease into itlike they’re trying not to offend the machine. Don’t. Give a confident, explosive start.

3) Keep your chin slightly up and sit tall

Good posture helps lungs expand fully. Sit upright with feet on the floor unless your technician instructs otherwise.

4) Cough happenstell the technician

If you cough mid-maneuver, let them know. They may repeat the blow. Coughing is common, especially for people with airway irritation.

5) If you used your rescue inhaler, be honest

Safety comes first. If you needed your rescue inhaler before the test, tell the staff what you used and when. That information helps interpret the results accurately.

Common Concerns (and Honest Answers)

“Is spirometry painful?”

Nospirometry isn’t painful. It can feel tiring because you’re exhaling forcefully several times. Some people feel lightheaded briefly. If that happens, tell the staff and take a break.

“What if I can’t do it ‘right’?”

You’re not expected to arrive already knowing how. Coaching is part of the process. The staff’s job is to help you produce your best effort safely. If you have trouble understanding the steps, ask them to demonstrate and talk you through it again.

“Will I get results immediately?”

Sometimes you’ll hear preliminary numbers, but interpretation often requires a clinician to review the results alongside your history and symptoms. If you’re curious, ask when and how you’ll receive your results.

Special Situations: Extra Prep Tips

If you have asthma

You may be instructed to hold certain inhalers before testing, especially if the goal is to measure baseline airflow. But don’t risk an asthma flarefollow the clinic’s plan and use rescue medication if needed. Tell the staff if you’re symptomatic when you arrive.

If you have COPD or chronic bronchitis

Bring a list of your inhalers and the times you last used them. Spirometry is often repeated to confirm consistent effort. If coughing is common for you, mention itstaff can pause between attempts and help you recover comfortably.

If you’re anxious (or hate “performance tests”)

Tell the technician you’re nervous. Truly. Many people do better when coaching is slower and more step-by-step. Take breaks if you feel dizzy. A calm, steady approach usually produces better data than trying to “power through” while stressed.

After Spirometry: What to Do Next

Most people can resume normal activities right away. If you were instructed to hold medications, ask when to restart them. If you feel lightheaded, sit for a moment, drink water, and stand up slowly. If the test triggered wheezing or coughing that doesn’t settle, notify the staff before you leave.

Real-World Experiences: What Spirometry Feels Like (and How People Get Through It)

Let’s talk about the part most instructions don’t capture: the human experience of spirometry. The test is simple on paperinhale, exhale, repeatbut real people have real reactions, and it helps to know what’s normal.

Experience #1: “Why am I being cheered on like this is a marathon?”
Many people are surprised by how energetic the coaching can be. The technician might say, “Big breath in… BLAST it out… keep going, keep going, keep going!” It can feel funny, but the goal is consistency. A strong start and a complete exhale help the machine measure your true capacity. People who do best often treat it like a short, controlled athletic effort: focus, blow, finish, rest.

Experience #2: The “Oops, I got dizzy” moment
A brief lightheaded feeling can happen, especially if you blow hard multiple times in a row. This doesn’t mean something is wrong; it usually means your breathing pattern changed quickly. People often say the best strategy is simple: tell the technician immediately, take a break, breathe normally, sip water, and restart when you feel steady. Trying to hide dizziness to “get it over with” can actually slow things down.

Experience #3: Coughing mid-test
If you have asthma, allergies, chronic bronchitis, or a sensitive throat, the forceful exhale can trigger a cough. This is extremely common. People who get the best results aren’t the ones who never coughthey’re the ones who communicate. When a cough happens, the staff can pause and repeat the attempt. Some patients find it helps to take a few calm breaths before the next blow and to keep the mouth seal tight, so air isn’t leaking around the mouthpiece.

Experience #4: “I kept messing up the timing”
First-timers often worry they’ll ruin the test by misunderstanding the steps. The reality: staff expect a learning curve. Many patients do better after one or two practice tries. A helpful mental image is to think “rocket launch”: inhale fully, then explode into the exhale immediatelyno gentle warm-upthen keep going until you’re told to stop. People who hesitate at the start can produce numbers that look artificially low, even if their lungs are okay.

Experience #5: The bronchodilator re-test surprise
Some patients don’t realize they’ll repeat spirometry after using an inhaler in the clinic. That’s not a trick; it’s a comparison. People often describe the second round as easierbreathing feels more openthough not always. The key is to do your best effort both times. Even if you feel better after the inhaler, you still need a strong, consistent blow for the comparison to be meaningful.

Experience #6: The emotional side of the numbers
For some, spirometry is just a routine check. For others, it’s loadedespecially if symptoms have been scary or persistent. Patients often say it helps to remember that spirometry is information, not a verdict. Your results are one piece of a bigger puzzle that includes your symptoms, history, exam, and sometimes imaging or other tests. If your numbers are abnormal, your clinician can explain what that pattern means and what next steps make sense.

The biggest “wins” people mention: arriving prepared (knowing medication instructions), wearing comfy clothes, avoiding a heavy meal, and being honest about symptoms. In other words: the boring prep stuff actually works. And that’s kind of beautifulbecause it means you can do a lot to make this test go smoothly before you ever blow into the tube.

Conclusion

Preparing for a spirometry procedure doesn’t have to be complicated. The goal is straightforward: show up in a state that lets the test measure your lung function accurately. That usually means following your lab’s medication instructions, skipping heavy meals and intense exercise right before testing, avoiding smoking/vaping, wearing loose clothing, and giving your best coached effort during the test.

If anything is unclearespecially which inhalers to take or holdask before test day. Accurate spirometry helps your healthcare team make better decisions, and that’s worth a quick call (or portal message) now so you’re not guessing later.