People are often concerned about being exposed to radiation during an X-ray. However, everyone is exposed to sources of natural radiation throughout their life.
Natural radiation is sometimes known as background radiation. Sources of background radiation include:
- radon: a naturally occurring radioactive gas that is found in low levels in the atmosphere
- cosmic rays: a type of radiation that originates from space (from the sun and stars)
- the earth: soil and rocks contain various radioactive materials that have been present since the earth was formed; these contribute to our exposure, as do building materials that are made from soil, rocks and stones
- food and water: for example, nuts, bananas, red meat and potatoes all contain tiny traces of radiation
Read more about radiation.
Cancer risk
Being exposed to X-rays does carry a theoretical risk of triggering cancer at a later date (as does exposure to background radiation). However, this risk is extremely low.
For example, the Health Protection Agency (HPA) has calculated that:
- an X-ray of your chest, teeth, arms or feet is the equivalent of a few days' worth of background radiation and has a less than 1 in 1,000,000 chance of causing cancer
- an X-ray of your skull or neck is the equivalent of a few weeks' worth of background radiation and has 1 in 100,000 to 1,000,000 chance of causing cancer
- an X-ray of your breasts (mammogram), hip, spine, abdomen or pelvis is the equivalent of a few months' to a year’s worth of background radiation and has a 1 in 10,000 to 100,000 chance of causing cancer
- an X-ray that uses a contrast fluid, such as a barium meal, is the equivalent of a few years' worth of background radiation and has a 1 in 1,000 to 10,000 chance of causing cancer
It is important to put the risk of developing cancer from X-rays into perspective. More than 1 in 3 people in the UK will develop some form of cancer during their lifetime.
Your risk of developing cancer depends on many factors, including your age, lifestyle and genetic make-up. You can read more about the risk of developing cancer on the Cancer Research UK website.
X-rays and pregnancy
The doses of radiation that are used during an X-ray are not thought to pose a risk to an unborn baby. However, as a precaution, X-rays that directly target the womb (abdominal X-rays) are not usually recommended unless there is a clear clinical need.
In some cases, an alternative method that does not involve radiation, such as an ultrasound scan, may be recommended.
Also as a precaution, before having an X-ray you may be asked the date of your last period. This is to check whether there is a chance that you could be pregnant.
Do not panic if you have an X-ray and later discover that you are pregnant. Even the most powerful types of X-rays, such as a barium enema, are not thought to have any adverse effects on the outcome of pregnancy.
