What is an X-ray? 

An X-ray is a test that creates images to let a doctor view the inside of the human body without having surgery, particularly giving a clear view of the bones. It is quick and painless and helps in accurate diagnosis and treatment for a variety of medical conditions. X-rays use electromagnetic radiation to capture images of the area being examined.  

Discovered in 1895 by Wilhelm Conrad Rontgen, the procedure has been used for decades. Rontgen did not understand the nature of the rays used in the test, he, therefore, called them X-rays, denoting to the mathematical equation where ‘x’ represents the unknown.

X-rays of different types are used for a variety of different purposes. Some examples include a mammogram examining your breasts and a barium enema which looks at your gastrointestinal tract. These types of X-rays give more detail on the specific area they are examining.  

How it works is that rays pass through the body and are absorbed in varying amounts which is dependent on the material density that the rays or beams are passing through.

Dense material such as bone and metal appear as white on the X-ray, whilst the lungs with air in them appear as black. Muscle and fat show up as different shades of grey.  

The following article is an overview article covering the basics on X-rays in order to get a thorough understanding and what they are, what they are used for, the procedure of having one done and more. This article is intended purely as a guideline and not as a professional opinion. Please consult with a doctor or healthcare professional for that. 

Why do I need an X-ray? 

Typically, X-rays are done in order to assess or examine an area causing discomfort or pain or to ascertain whether a bone is broken after an accident or trauma, they also monitor how well a treatment is working, the body is healing and to track the progression of a disease that has been previously diagnosed, such as osteoporosis (a condition where the bones become weak and fragile).  

X-rays are used to examine different parts of the body, these can include:  

Teeth and bones 

  • Fractures and infections in the bones– these show up clearly in X-rays.  
  • Arthritis affecting the joints X-rays help your doctor to detect, monitor and track progression of the conditions, noting if it is getting better or worse through comparing years of X-rays.  
  • Osteoporosis this is detected and monitored through measuring bone density through special types of X-ray.  
  • Dental decayinvolves using X-rays to check for cavities in the teeth.   
  • Bone cancer X-rays reveal bone tumours.  


  • Digestive tract issuesare detected using a barium enema or liquid, which is a swallow test that gives a visual representation of the digestive tract through the use of an X-ray. The liquid is swallowed or delivered in an enema (injecting the liquid into the rectum) and passed through the body to allow areas with an issue to be detected.  
  • Items swallowed – if something has been swallowed by accident that the body cannot digest, which occurs in cases with children regularly, an X-ray can detect the item and its position in the digestive tract. 


  • Lung conditions – X-rays can detect evidence of tuberculosis, pneumonia and lung cancer 
  • Breast cancer  using a mammogram, which is a special type of X-ray test that is used to assess the tissue of the breast and detect any abnormalities such as lumps that could possibly be cancerous.    
  • Enlarged heart  X-rays are able to clearly detect any signs of congestive heart failure.   
  • Blocked blood vessels – these are detected through injecting a material that is able to show up clearly on an X-ray intravenously (into your vein), known as a contrast material. It normally contains iodine, which highlights specific areas of the circulatory system to clearly appear on the X-ray.  If you are allergic to iodine it is important to tell your doctor and radiographer (the person performing the X-ray) so that an alternative contrast can be used.

How should I prepare for an X-ray? 

Having an X-ray is a standard procedure, and often does not involve any special preparational steps. However, different X-rays require different preparations. It is best to speak to your doctor about how you should prepare.  

X-ray shown on computer screen
It is the general rule that you will undress the area of your body that
 is being examined, you may sometimes be asked to wear a gown. You will have to remove any items of metal, jewellery and eyeglasses. It is sometimes best to wear loose-fitting clothing without metal zips that you can easily move around in, should you not be asked to put on a gown.  

Always inform your doctor about any metal implants you may have from previous surgeries, as these can stop the X-ray beams from passing through the body to create a clear and concise image.  

When contrast material or dye is used for the X-ray, you will need to swallow or ingest the liquid through an enema (the solution is inserted into the body through the anus), it can also be injected into your body. 

With an X-ray that examines your gastrointestinal tract, you may be asked to not eat for a certain amount of time before the X-ray, and you may also not be able to drink any liquids – this aids in creating a clearer X-ray in having an empty digestive tract.  

What happens to me during an X-ray? 

The procedure will be performed wherever there is an X-ray machine. It can be performed in doctors’ rooms, dentists’ rooms, hospitals, emergency rooms as well as radiology clinics who specialise in procedures that are diagnostic 

Once you are ready and prepared, the radiologist or X-ray technician will direct you on how to position your body. You may have to stand, sit or even lie down. You will have to stay extremely still in order to get a clear X-ray image. The radiologist may even use pillows to help to hold you in place. It is sometimes necessary to hold your breath in order to be extremely still.   

In some cases, you may be asked to stand in front of a specialised plate containing sensors or X-ray film. Or you may have to lie or sit on the plate and then a camera will be moved over your body that is connected to a steel arm to capture the X-ray images.  

You cannot feel an X-ray, it is completely painless.

It can take a few minutes (mostly for teeth and bone X-rays), or may even take more than an hour (specifically for treatments using a contrasted medium). When your radiologist is happy with the images that have been captured, your test is finished.  

What happens if a child has an X-ray?  

If a child has an X-ray, they may be kept in place with certain restraints, in order to keep them as still at possible. The restraints will not harm the child. The parent is sometimes allowed to stay with them for the duration of the test – in this situation, the parent may be asked to wear a lead apron to shield them from unnecessary and possible exposure to radiation which X-rays give off. 

How does an image get produced during an X-ray?  

X-rays use beams that come into contact with the tissue in the body, certain tissue absorbs the high-energy rays differently and can result in the beam passing through them, dense material absorb the beams and show up clearly on the produced image on a metal film.  

What happens after an X-ray? 

Once the radiologist has collected the images of the X-ray, you will change back into your clothes, if you were wearing a gown, and depending on your specific condition, your doctor will probably allow you to leave and go about your daily activities, or go home and rest whilst you wait for your results. The results may be ready within a few days after the procedure or on the actual day, depending on how busy the radiologist compiling the report is.  Radiologists will generally not discuss your results with you, even if you ask, as they do not give a diagnosis based on their findings, but rather leave this to your doctor who has your full medical history and list of symptoms.

As such, your radiologist will send your X-rays and a report to your doctor for him/her to compile their own report from there, based on the results. Your doctor will then determine the diagnosis and proceed accordingly, he/she may also order more additional tests in order to ensure an accurate diagnosis such as blood tests or additional scans, which may be followed by medication or other forms of treatment.  

What are the side effects after an X-ray? 

To create the images for the X-ray of the different parts of your body, the X-ray will use small amounts of radiation, however, the level of exposure is considered safe for older children and adults. While it is highly unlikely that an X-ray will cause harm to a developing baby during pregnancy, most doctors will err on the side of caution and avoid these as far as possible. It is recommended that the doctor is informed if you are pregnant or suspect that you may be pregnant as he/she may suggest a different imaging method, such as an MRI (magnetic resonance imaging), which is a popular alternative.  

MRI Machine

If the X-ray is being conducted to examine a painful condition or a broken bone, you can expect to experience a level of discomfort or pain as you will have to position your body in a specific way so as to get an accurate image. In this situation, your doctor may recommend you take pain medication before the X-ray.  

The ingestion of contrasting material for an X-ray may result in:  

  • Nausea
  • Itching 
  • Feeling faint
  • A metal taste in your mouth 
  • Hives 

In some very rare cases, the dye or contrasting material can result in anaphylactic shock, cardiac arrest or severely low blood pressure. If any of these symptoms are suspected, the radiographer will be trained to deal with them and if they occur once you have left the radiologist or X-ray department, consult with your doctor immediately.  

What are the results of an X-ray? 

X-rays are digitally saved on computers and are accessed and viewed within a few minutes by the radiologist. They will then compile a report for your doctor based on the results. This report will be explained to you by your doctor. If the situation is an emergency, the results and report can be given to your doctor in a matter of minutes.  

Disclaimer - MyMed.com is for informational purposes only. It is not intended to diagnose or treat any condition or illness or act as a substitute for professional medical advice.