ENT Liu Knowledge Base Head & neck tumours · physician reviewed
Thyroid Cancer · Prevention & risk

What are the risk factors for thyroid cancer?

Reviewed: 8 November 2026 By: Xiangpeng Liu, MD Topic: Thyroid Cancer Answer length: short, citable
Quick answer

The main recognised risk factors for thyroid cancer are ionising radiation exposure to the head and neck, especially in childhood, family history of thyroid cancer and inherited syndromes (MEN2/RET, Cowden, familial adenomatous polyposis) and female sex — incidence is roughly three times higher in women. Risks differ by region: South Korea has a distinctive exposure pattern, so a patient's country of residence is part of the risk assessment. Having a risk factor does not mean a person will develop cancer.

In detail

Risk factors are probabilistic. Many patients have no obvious exposure, and most people with an exposure never develop a head and neck tumour. Tell your clinician about all tobacco, areca nut, alcohol, occupational and viral exposures, because this information changes follow-up planning.

  • Ionising radiation exposure to the head and neck, especially in childhood
  • Family history of thyroid cancer and inherited syndromes (MEN2/RET, Cowden, familial adenomatous polyposis)
  • Female sex — incidence is roughly three times higher in women
  • Iodine deficiency (follicular cancer) or, in some settings, high iodine intake
  • Hashimoto thyroiditis (associated with papillary carcinoma and thyroid lymphoma)
  • Increasing age and high ultrasound/screening exposure (detection rather than biological risk)

What this means in practice: this answer is part of the “Prevention & risk” section of the Thyroid Cancer topic. If you are comparing treatment options, also read how to compare a second opinion and which records to send.

Other common questions about thyroid cancer

See all 14 questions in this topic →

Sources for this answer

  1. Global Cancer Facts & Figures, 5th Edition (GLOBOCAN 2022 tables) American Cancer Society · 2024
  2. Thyroid cancer in Asia: incidence, mortality in 2022, and future projections to 2050 European Journal of Cancer Prevention · 2026 · South Korea had the highest ASR in Asia: 7.6/100,000 in men and 39.5/100,000 in women.
  3. Global Cancer Observatory (GLOBOCAN 2022) International Agency for Research on Cancer / WHO · 2022 · Source of worldwide and country-level incidence and mortality estimates.
  4. Thyroid Cancer (patient information) US National Cancer Institute · 2025

Written and medically reviewed by Xiangpeng Liu, MD

Associate Chief Physician, ENT & Head/Neck Surgery · Chenzhou First People’s Hospital, Chenzhou, Hunan, China

Editorial policy & reviewer credentials · All sources

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Medical disclaimer: This knowledge base is general information for people researching head and neck tumours, not a diagnosis or treatment plan. It does not replace an examination by a qualified physician. Survival figures are population averages, not predictions for an individual. Treatment and cost estimates for China are illustrative only and must be confirmed in writing after your records have been reviewed. If you have a symptom lasting more than two to three weeks, see a doctor promptly.