What Is a Pulmonary Function Test? Uses, Types and Preparation

What is a pulmonary function test?

A pulmonary function test (PFT) is a group of painless breathing tests that measure how much air your lungs hold, how fast you can move it in and out, and how well oxygen passes into the blood. Doctors use pulmonary function tests to diagnose and monitor asthma, chronic obstructive pulmonary disease (COPD) and other lung conditions. There are no needles, no radiation and no enclosed space.

The most familiar part is spirometry, the forceful blow into a mouthpiece you may have seen in health camps. A full PFT session at KDRC can also include lung volume measurement and diffusion capacity, giving a complete picture of your lung health in about 30 to 45 minutes. MedlinePlus explains that diffusion capacity is measured by breathing a harmless tracer gas, often for a single breath. Appointment details are on our PFT test in Pokhara page.

The test turns symptoms into numbers. Instead of guessing why you are breathless, your doctor can see whether the airways are narrowed, whether the lungs are smaller than expected, or whether oxygen transfer is reduced, and then choose treatment that matches how your lungs actually behave.

When do you need a lung function test?

Many people live with breathlessness for years, putting it down to age or smoke. These are the common reasons doctors order a PFT.

• Long-standing cough. A cough lasting more than two months deserves a proper look at lung function.
• Wheeze or chest tightness. Whistling breath and tightness are classic airway signs, especially at night or with exercise.
• Breathlessness out of proportion to effort. Tiring quickly on stairs and slopes is not always just fitness.
• Confirming asthma or COPD. The NHS lists finding out whether symptoms are caused by asthma, COPD or pulmonary fibrosis as a main reason for spirometry.
• Monitoring treatment. Repeating the test shows whether inhalers are working.
• Before surgery or for work. PFTs check lung fitness before major operations and monitor workers exposed to dust and fumes.

In Pokhara, kitchen smoke, road dust, vehicle fumes, tobacco and burning rubbish irritate airways daily. Frequent "bronchitis" episodes in smokers also warrant checking. If you have smoked for years or worked around smoke, dust or fumes, a baseline PFT is worth discussing with your doctor.

How to prepare for a PFT at KDRC

Good preparation makes the numbers accurate on the first attempt. KDRC staff confirm the details, including inhaler timing, when you book.

Food, smoking and exercise

Avoid smoking and heavy exercise for 8 hours before the test and heavy meals for 2 hours, because a full stomach restricts deep breathing. A light meal a couple of hours before is fine. Avoid tea, coffee and smoking on the day, and wear loose, comfortable clothing, since tight clothes restrict deep breaths.

Inhalers and medicines

Inhalers usually need pausing for a set number of hours, and KDRC staff tell you exactly which ones when you book, because they can make an untreated airway look better than it is. Never stop any medicine on your own; confirm with staff or your doctor first, and bring your inhalers with you.

Health issues to mention

Tell staff about loose teeth, recent eye, chest or abdominal surgery, a recent heart attack, a collapsed lung or a recent coughing fit, because forceful blowing may need adjusting or delaying.

Spirometry vs full PFT: which do you need?

Spirometry measures how much air you can blow out and how fast. It is quick and enough for many questions, such as checking for asthma or COPD. A full PFT adds lung volume measurement and diffusion capacity, which helps when the lungs may be restricted in size or when oxygen transfer is in question.

Spirometry alone costs less but answers fewer questions than a full PFT with reversibility testing. Your doctor's referral decides which you need, and KDRC staff can advise what the referral calls for. The cost of a PFT varies with the number of test components; KDRC quotes transparently before you book, so call 061-553538 for current pricing. Our guide to choosing a diagnostic centre in Pokhara explains how to compare quotes like with like.

For a fuller explanation, read spirometry vs full PFT.

What happens during a PFT at KDRC?

At KDRC Pokhara you sit upright wearing a nose clip and breathe through a mouthpiece connected to the machine. The technologist coaches you through each manoeuvre so the numbers are accurate. Forceful exhaling can feel tiring for a moment; that effort is part of the test, not a sign of anything wrong.

The full session takes 30 to 45 minutes including rest periods and, if requested, reversibility testing, so plan about an hour at the centre. The NHS spirometry guide notes that using an inhaler and repeating the test after a short break shows whether the inhaler affects your result.

PFT results and safety

Your results are compared with predicted values for your age, height and sex. Two numbers matter most: FVC, the total air you can blow out, and FEV1, the air you blow out in the first second. Their ratio separates obstructive patterns, such as asthma and COPD, from restrictive ones where total lung volume is reduced. The NICE COPD guideline uses an FEV1/FVC ratio below 0.7 after an inhaler as a key sign of airflow obstruction. Reversibility helps tell asthma, which usually opens up with an inhaler, from COPD, which opens up little.

Early diagnosis matters. According to the WHO, tobacco smoke and household air pollution from cooking fuels are major causes of COPD. For smokers, the FEV1 trend over the years is one of the clearest warning signals, and decline can be slowed by quitting and starting treatment early. Your doctor interprets the report with your symptoms; for a line-by-line walkthrough see lung function test results explained.

A PFT is non-invasive and safe for most people. Forceful blowing can briefly cause dizziness or coughing that settles in minutes, and the technologist paces the test. MedlinePlus notes a small risk of a collapsed lung in people with certain lung diseases, which is why staff check your history first.

Common mistakes and myths about PFT

• Myth: breathlessness is just age. Many people normalise treatable airway disease for years.
• Mistake: stopping medicines without advice. Pause inhalers only as KDRC staff or your doctor advise.
• Mistake: smoking or eating a big meal beforehand. Both can lower your numbers and lead to a repeat.
• Myth: a PFT is painful. You only breathe into a mouthpiece; brief tiredness is normal.
• Mistake: holding back on the blows. Maximum effort gives accurate results, so follow the coaching.
• Myth: one normal test means lungs are fine forever. Smokers and dust-exposed workers benefit from repeat testing.

A PFT can change a decade of wrong assumptions in under an hour. KDRC also offers 192-slice CT for chest imaging, so related tests can often be done in one visit. Read about lung function testing at KDRC or contact KDRC at Shantipath, Amarsingh Chowk, on 061-553538 or 9856077433.