Why Do Doctors Recommend Oxygen Therapy? Common Conditions Explained

“Why has the doctor put my father on oxygen?” is one of the most common questions families ask us at Electromed Corporation, usually right after a hospital visit or a pulmonologist’s appointment in Lahore, Karachi, Islamabad, or Peshawar. Oxygen therapy can sound alarming the first time it’s mentioned, but in most cases it’s simply a doctor correcting a measurable shortfall — the blood isn’t carrying enough oxygen to the body’s organs, and supplemental oxygen fixes that gap safely. Here’s a clear look at the conditions that most often lead to an oxygen prescription in Pakistan, and how doctors actually decide when it’s needed.

What Oxygen Therapy Actually Treats

Oxygen therapy doesn’t treat a disease directly — it treats low blood oxygen (hypoxemia), which is a result of many different diseases. When the lungs can’t transfer enough oxygen into the bloodstream, or the heart can’t circulate oxygen-rich blood efficiently, the body’s tissues run short. Supplemental oxygen, delivered through a nasal cannula from a concentrator or cylinder, raises the oxygen available in each breath so the blood can carry a normal amount again. That’s why the same therapy shows up across such a wide range of conditions — the common thread is low oxygen, not any single illness.

COPD and Chronic Lung Disease — the Most Common Reason in Pakistan

Chronic Obstructive Pulmonary Disease (COPD) remains the single biggest reason adults in Pakistan end up on long-term home oxygen. Years of smoking, exposure to Lahore and Karachi’s smog, or decades of cooking over biomass and wood fires in rural kitchens gradually damage the lungs’ ability to move oxygen into the blood. As COPD advances, doctors typically check blood oxygen with a pulse oximeter or an arterial blood gas test, and once saturation drops persistently into the high-80s or below, oxygen therapy is usually recommended — often for daily, ongoing use rather than just during flare-ups. We’ve covered this in detail in our earlier piece on COPD symptoms, causes, and how home oxygen therapy helps.

Severe Chest Infections and Pneumonia

A bad chest infection or pneumonia can temporarily drop blood oxygen even in someone with otherwise healthy lungs, because inflamed, fluid-filled airways can’t exchange gas properly. This is especially common during Pakistan’s winter smog season, when hospitals in Lahore and Karachi see a sharp rise in chest infections among both children and the elderly. In many cases, oxygen support is needed only for a short recovery window — days to a few weeks — until the infection clears and lung function returns. We discussed the warning signs to watch for in our guide to chest infection warning signs in Pakistan.

Pulmonary Fibrosis and Other Interstitial Lung Diseases

Pulmonary fibrosis causes scarring deep in the lung tissue, which stiffens the lungs and makes it progressively harder for oxygen to pass into the bloodstream — even when airflow itself isn’t obstructed the way it is in COPD. Patients with fibrosis often need oxygen earlier during physical activity than at rest, which is one reason doctors frequently test oxygen levels both sitting still and while walking before deciding on a prescription.

Heart Failure and Circulatory Conditions

Not every low-oxygen situation starts in the lungs. In heart failure, the heart struggles to pump blood efficiently, so even well-oxygenated blood doesn’t reach the body’s tissues fast enough, and fluid can build up in the lungs themselves and interfere with gas exchange. Cardiologists sometimes prescribe supplemental oxygen alongside heart medication in these cases, particularly when a patient’s oxygen saturation drops during exertion or sleep.

Post-COVID Lung Recovery

Several years on from the pandemic, pulmonologists in Pakistan still see patients whose lungs haven’t fully bounced back after a serious COVID-19 infection, particularly those who needed hospital oxygen at the time. For some, temporary home oxygen support during recovery — alongside breathing exercises and follow-up scans — helps the body heal without the added strain of chronic low oxygen. This is typically reassessed every few weeks, since lung function in post-COVID patients often keeps improving over months.

Sleep-Related Low Oxygen

Some patients, especially those who already have COPD or are significantly overweight, experience oxygen levels that drop specifically during sleep — sometimes alongside obstructive sleep apnea. Doctors call the combination of COPD and sleep apnea “overlap syndrome,” and it often needs a tailored approach: a CPAP machine to keep the airway open, supplemental oxygen to correct nighttime desaturation, or occasionally both together, depending on what an overnight oximetry or sleep study shows.

How Doctors Actually Decide

Across all of these conditions, the decision follows a similar pattern: a doctor measures blood oxygen saturation with a pulse oximeter (a simple clip-on sensor, usually on a fingertip) or, for a more precise reading, an arterial blood gas test. Oxygen therapy is generally considered once saturation falls persistently to around 88% or below at rest, or drops significantly during exertion or sleep even if resting levels look fine. This is a clinical decision that also weighs the underlying condition, how it’s expected to progress, and whether the low oxygen is affecting the heart or other organs — which is exactly why self-diagnosing with a home pulse oximeter and buying oxygen “just in case” isn’t a safe substitute for an actual medical assessment.

Matching the Machine to the Prescription

Once a doctor has written a prescription with a specific flow rate, the next step is practical: getting a machine that actually delivers it reliably. Patients on lower prescribed flows often do well with a 5 LPM concentrator, while those with more advanced disease or higher flow needs may be prescribed a 10 LPM concentrator. Patients who are still active and need to move between rooms, travel, or attend family events often prefer a portable oxygen concentrator instead of being tied to a stationary unit. If you’re not sure which category fits your prescription, our team at Electromed Corporation can talk you through it — reach out to our Lahore, Karachi, Islamabad, or Peshawar branches and bring your doctor’s prescribed flow rate with you.

This article is for general information only and is not a substitute for professional medical advice. Please consult your doctor or a pulmonologist to confirm whether you or a family member needs oxygen therapy, and always follow their prescribed flow rate and schedule.