X-ray imaging: when it helps and what it can show

An X-ray is a common imaging test that uses a small amount of ionising radiation to create images, primarily of bones and certain structures in the chest. In UK general practice, X-rays are used to answer specific clinical questions, for example to assess for a fracture after injury or to evaluate certain chest symptoms.

This page explains what X-rays can and cannot show, when a GP is likely to recommend one, how radiation risk is considered, and what to expect before and after your X-ray.

These articles are intended as educational sources, not diagnostic nor taking place of a proper medical assessment. If you need help or advice on medical scans, please book a GP appointment.

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How X-rays commonly help in GP care

X-rays are most helpful when they are used to answer a focused question, such as:

Is there a fracture after a fall or injury?
Is there evidence of significant joint change, such as osteoarthritis?
Is there a chest cause that needs assessment, such as pneumonia in the right context?
Is there a complication that needs urgent escalation?

X-rays are less useful for conditions where the suspected problem is in soft tissues such as muscles, tendons, ligaments, or discs.

What an X-ray can and cannot show

What X-rays are useful for

X-rays are particularly useful for:

Bones and fractures
Joint alignment and dislocation
Some forms of advanced joint disease, including osteoarthritis
Chest imaging, including lung fields and heart size in selected contexts
Foreign bodies in some situations

What X-rays are less helpful for

X-rays do not show soft tissues well, so they are limited for:

Muscle strains and tendon injuries
Ligament or meniscal injuries in the knee
Most causes of back pain that are not related to fracture or serious pathology
Early inflammatory arthritis changes, where ultrasound or MRI may sometimes be more informative

A GP chooses imaging based on which test best answers the clinical question.

Common reasons a GP may recommend an X-ray

After injury

An X-ray may be recommended if there is concern about fracture or dislocation, particularly when there is:

Significant pain and bony tenderness
Inability to weight bear or use the limb normally
Visible deformity
High-risk mechanisms of injury

Joint symptoms

An X-ray may be considered for:

Persistent joint pain and stiffness where osteoarthritis is suspected
Reduced function that is not improving
Planning referral pathways where imaging is required

Chest symptoms

A chest X-ray may be considered when clinically appropriate, for example:

Persistent cough with concerning features
Suspected pneumonia based on symptoms and examination
Unexplained breathlessness in selected cases

A chest X-ray is not required for every cough. The decision depends on the pattern, duration, and risk factors.

Seek urgent medical advice if you develop:

Severe pain after injury with deformity or inability to move a limb
New weakness, numbness, or loss of bladder or bowel control
Severe chest pain, significant breathlessness, or coughing up blood
High fever with worsening symptoms and feeling acutely unwell

How a GP decides whether an X-ray is appropriate

A GP will consider:

Your symptoms and the pattern of illness or injury
Examination findings where available
Whether an X-ray would change what happens next
Whether another test is more appropriate
Whether there are red flag features

For the GP approach to imaging decisions, see:
How GPs use medical imaging in practice

Preparing for an X-ray

Most X-rays require little preparation. You may be asked to:

Remove metal objects or jewellery near the area being imaged
Change into a gown in some settings

If you are or may be pregnant, tell the radiology team before the X-ray. This is especially important for imaging of the abdomen or pelvis.

What happens during the X-ray

X-rays are usually quick:

You may be asked to stand, sit, or lie in a specific position
Several images may be taken from different angles
For chest X-rays, you may be asked to take a deep breath and hold it briefly

Most appointments take only a few minutes.

Radiation and safety: how much risk is there?

X-rays use ionising radiation, but the dose for most standard X-rays is low. In general practice, the benefits of an X-ray usually outweigh the small risks when the test is clinically indicated.

GPs avoid unnecessary X-rays because:

Many symptoms improve without imaging
Incidental findings can create anxiety
X-rays may not show the cause of symptoms in soft tissue problems

If a different test is more appropriate, a GP will usually recommend that instead. no problem. It means the scan did not show a structural cause that ultrasound can detect.

Limitations and common misunderstandings

A normal X-ray does not always mean nothing is wrong

Some problems do not show on X-ray, particularly soft tissue injuries.

An abnormal X-ray does not always explain symptoms

Age-related changes, such as mild degenerative changes, are common and may not be the cause of pain.

X-ray results should always be interpreted in the context of symptoms and examination.

What happens after an X-ray

If the X-ray explains symptoms

A GP may:

Confirm the likely diagnosis
Recommend treatment
Arrange follow-up
Refer to specialist care if needed

If the X-ray is normal