Thyroid cancer
Anything that can increase your risk of getting a disease is called a risk factor.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will definitely get that cancer.
Thyroid cancer is more common in women than in men during their reproductive years. It peaks in women between the ages of 40 and 44 years. Men are more likely to develop thyroid cancer at an older age. It is most common in men aged between 75 and 79.
The reasons for this are still unclear. Researchers are looking at the relationship between thyroid cancer and:
pregnancy
the use of
the age periods start
the age of
surgery to remove your ovaries and/or womb
The risk of thyroid cancer is higher in people who are or .
Some non cancerous (benign) thyroid conditions increase your risk of thyroid cancer. These include:
an enlarged thyroid gland (goitre)
a condition where the attacks the thyroid gland (Hashimoto's disease)
thyroid adenomas – these are growths that develop in the thyroid gland and are a type of thyroid
a condition where the thyroid produces too much of the hormones T3 and T4 (hyperthyroidism)
Thyroid lumps are common. But less than 10 out of 100 thyroid lumps (less than 10%) are cancer.
You have a higher risk of thyroid cancer if a close family member has thyroid cancer. A close relative is a parent, brother, sister, son or daughter. But it’s worth remembering that this risk is still very small because thyroid cancer is rare.
Speak to your GP if you are concerned about your family history of thyroid cancer.
Some people have an increased risk of thyroid cancer because of an .
Some people have changes in the RET gene that cause syndromes called MEN2A and MEN2B. MEN stands for multiple endocrine neoplasia. People with these syndromes have an increased risk of medullary thyroid cancer.
MEN2A and MEN2B are rare conditions. Most people found to have MEN are offered surgery to remove their thyroid gland. About 25 in every 100 people (about 25%) who develop medullary thyroid cancer have an inherited faulty gene associated with MEN.
Familial adenomatous polyposis (FAP) is a bowel condition caused by an inherited gene. Some studies suggest that people with FAP might have an increased risk of thyroid cancer.
You have an increased risk of thyroid cancer if you have Cowden syndrome. Cowden syndrome is a rare inherited disorder. It causes lots of non cancerous (benign) growths called harmatomas. People with this disorder have an increased risk of cancer.
Read more about screening for thyroid cancer
The thyroid gland is sensitive to . People who have a lot of radiation may develop nodules or lumps on their thyroid some years later. A lump or nodule on your thyroid doesn’t always mean it is a cancer. But you should always check with your doctor if you find a lump.
Thyroid cancer is more common in people treated with radiotherapy when they were a child. The cancer might develop some years later. It is also more common in people who had dental before 1970. And the risk of thyroid cancer is higher in people who had of the brain, head and neck when they were children.
Research has looked at people routinely exposed to radiation through their work. This has not shown an increase in their risk of thyroid cancer. More research is needed.
Thyroid cancer may be more common in survivors of atomic explosions or accidents. Thyroid cancer cases rose in the Ukraine after the Chernobyl nuclear reactor accident. Thyroid cancer increased in people exposed when they were children or adolescents.
Some people have low levels of iodine in their body. They might have a higher risk of thyroid cancer after exposure to radioactive iodine. This is compared to people with normal iodine levels.
Acromegaly is a rare condition where the body over produces growth hormone. Studies suggest that this may increase the risk of thyroid cancer.
is an . Studies suggest that thyroid cancer risk is higher in people with this condition.
Some studies suggest that people treated as adults for certain cancers have an increased risk of thyroid cancer. These include:
cancer of the food pipe (oesophageal cancer)
breast cancer
It is not known if this is due to treatment for these cancers, common risk factors or inherited genetic changes. In the case of oesophageal cancer, it may be because doctors find thyroid cancer during routine checks after treatment.
We have more detailed information for health professionals about thyroid cancer risks and causes.
For detailed information go to the Cancer Statistics section
Stories about possible cancer causes are often in the media and it can be hard to know what’s true and what’s not. You may have heard of something that isn’t included here. This is because we only include a risk factor in this information if it is supported by good quality evidence.
Find out about common cancer myths and questions on the causes of cancer
There are ways you can reduce your risk of cancer.
Last reviewed: 28 Aug 2026
Next review due: 08 Aug 2029
You usually start by seeing your GP. They will ask about your symptoms. They might refer you to a specialist and organise tests.
The type of thyroid cancer refers to the type of cell the cancer started in. The stage of a cancer tells you its size and whether it has spread.
Possible treatments include surgery, radiotherapy, targeted drugs and chemotherapy. What treatment you have depends on your type and stage of thyroid cancer.
The thyroid is a small butterfly shaped gland that makes and releases hormones. It’s found at the front of your neck in the lowest part.
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