There are a lot of people who seem to be more prone to becoming hypothyroid than others. Various factors may be involved in increasing their risk levels.

For example:

Women, especially those over 40

Women within 6 months after delivery

People with past record of thyroid disorder

People with high cholesterol

People experiencing depression

People with a family history of autoimmune thyroid disease

People who have had x-ray therapy of the head or neck for cancers or Hodgkin's disease

People who have taken or who are taking lithium or amiodarone

People with non thyroid autoimmune disease, for example:

Addison's disease, Type I diabetes, Pernicious anaemia, Rheumatoid arthritis, Systemic lupus erythematosus, vitiligo