Medically reviewed by Prof. Dr. Aamer Nadeem Chaudhary, M.B.B.S., D.M.R.D., F.C.P.S. (Diagnostic Radiology), Consultant, Al-Nasar Lab & Diagnostic Centre. Updated September 2026.
Quick answer: A chest X-ray is a single image of the lungs, heart, ribs and diaphragm. It takes seconds, needs no preparation and uses a very small radiation dose. It is the first test for cough, fever, chest pain and breathlessness, and it detects pneumonia, tuberculosis, fluid around the lungs, an enlarged heart and rib fractures.
Book a chest X-ray: call 0300 0341944. Home and bedside X-ray is also available across Lahore.
What can a chest X-ray detect?
| Finding | What it points to |
|---|---|
| Patchy or dense opacity | Pneumonia or another chest infection |
| Cavities and upper zone shadowing | Tuberculosis, which remains common in Pakistan |
| Fluid at the lung base | Pleural effusion, from infection, heart failure or other causes |
| Air outside the lung | Pneumothorax, a collapsed lung, which can be an emergency |
| Enlarged heart shadow | Cardiomegaly, often related to heart failure or long standing hypertension |
| Rib and clavicle fractures | After injury or a fall |
| Masses and nodules | Need further characterisation, usually with CT |
| Tube and line position | Checking a central line, endotracheal tube or pacemaker lead sits correctly |
| Air under the diaphragm | A perforated abdominal organ, a surgical emergency |
What is the difference between PA, AP and lateral views?
These abbreviations appear on almost every report and confuse most patients.
PA means posteroanterior. You stand facing the plate with the X-ray beam passing from your back to your front. This is the standard view and the best one, because the heart sits close to the plate and appears at its true size.
AP means anteroposterior. The beam passes front to back, used when a patient cannot stand, for example on a ward or with a portable machine. It is perfectly diagnostic, but the heart is magnified, so an AP film should not be used to judge heart size.
Lateral is a side view. Because a PA film hides parts of the lung behind the heart and diaphragm, a lateral view is added when something needs localising or when the PA looks equivocal.
Why are you told to take a deep breath and hold it?
Two reasons, and both affect whether the film is diagnostic.
First, a full breath in pushes the diaphragm down and opens the lungs, so more lung tissue is visible and subtle shadows are not compressed out of view. A film taken in poor inspiration can make normal lungs look crowded and abnormal, leading to unnecessary worry and repeat imaging.
Second, holding still eliminates blur. The exposure is a fraction of a second, but breathing during it softens the lung markings.
You will also be asked to roll your shoulders forward. That moves the shoulder blades out of the lung fields.
What a chest X-ray cannot tell you
This is worth stating plainly, because a normal chest X-ray is often taken as an all clear when it is not.
A chest X-ray flattens a three dimensional chest into one image. Structures overlap. Around a quarter of the lung is hidden behind the heart, the diaphragm and the ribs.
As a result it can miss early tuberculosis, small lung nodules, early interstitial lung disease and small pulmonary emboli. It also cannot assess the coronary arteries, and a normal chest X-ray says nothing about whether you are at risk of a heart attack.
When symptoms persist despite a normal film, the next step is usually an HRCT chest, which shows lung tissue in far greater detail.
When should you have a chest X-ray?
- Cough lasting more than two to three weeks
- Fever with breathlessness or chest pain
- Coughing up blood, which always requires imaging
- Suspected pneumonia or tuberculosis
- Chest injury after a fall or accident
- Sudden severe breathlessness
- Before surgery, as part of a fitness assessment
- For employment, visa or immigration medicals
- Monitoring a known chest condition or checking response to treatment
How much radiation is involved?
Very little. A chest X-ray is one of the lowest dose examinations in radiology, far lower than a CT scan of the same region.
That said, no X-ray should be done without a reason. The principle applied is to keep exposure as low as reasonably achievable, use the right test for the question, and avoid repeating an image that already exists. Bring previous films with you, because comparison often answers the question without any new exposure at all.
In pregnancy, chest X-rays are avoided unless genuinely necessary. When one is unavoidable, abdominal shielding is used and the dose to the baby is extremely small. Always tell the radiographer if you are or might be pregnant.
How to prepare
- No fasting and no preparation are needed
- You will change into a gown or remove clothing from the waist up
- Remove necklaces, chains and anything metal, as they cast shadows over the lungs
- Long hair should be tied up and out of the field
- Bring previous chest X-rays and your referral letter
- Tell the radiographer if you are or might be pregnant
- The whole visit usually takes only a few minutes
Chest X-ray at Al-Nasar Lab
Al-Nasar Lab & Diagnostic Centre has served Lahore since 1996 and holds ISO 15189:2022 accreditation from the Pakistan National Accreditation Council. X-ray is reported by consultant radiologists, and for patients who cannot travel we provide home X-ray for elderly and bedridden patients across Lahore. Our guide on when you need a portable X-ray explains how that service works.
Contact us to book or find your nearest location.
Frequently Asked Questions
How long does a chest X-ray take?
The exposure itself is a fraction of a second. Including changing and positioning, the whole visit usually takes only a few minutes.
Do I need to fast for a chest X-ray?
No. There is no preparation at all. You simply remove metal objects and clothing from the waist up.
Can a chest X-ray detect tuberculosis?
It often shows changes suggestive of TB, particularly in the upper zones, but early disease can be missed and confirmation requires sputum or laboratory testing.
Does a normal chest X-ray mean my lungs are healthy?
Not necessarily. Parts of the lung are hidden behind the heart and diaphragm, and early disease can be invisible. If symptoms continue, an HRCT chest is the usual next step.
Is a chest X-ray safe in pregnancy?
It is avoided unless necessary. When required, shielding is used and the dose to the baby is extremely small. Always tell the radiographer if you are or might be pregnant.
This article is for general information and is not a substitute for medical advice. Please discuss your results with a qualified doctor.
