Hi, I'm Dr. Mary Ann Block, Physician, Author and Medical Director of The Block Center in Dallas/Fort Worth, here for About.com. There are many different factors that can contribute to developing thyroid disease or thyroid problems. In this video, I'll take a look at some of those key factors. First of all, your gender plays a big role. Women have a bigger risk of developing thyroid disease than men. Anywhere from 6 to 8 times more likely.Secondly, your age. Both men and women 50 years or older have a greater risk of developing a problem with the thyroid.Family history is another risk factor. If you have a family history of thyroid problems or diseases, you are more likely to have problems yourself. The risk is a bit higher if a first-degree female relative has thyroid disease - like a mother or sister.The risk of developing thyroid disease also increases slightly during pregnancy and in the post-partum period, the first year after giving birth.Having major stress, due to, for example life-changing events such as death of a loved one, or a car accident - is also considered an environmental factor for thyroid disease.And if you are or were a smoker, you also have an increased risk of developing thyroid disease. That's because cigarettes contain thiocyanate, a chemical that affects the thyroid gland.Certain foods can also contribute to developing a problem with the thyroid. Certain foods naturally contain chemicals, called goitrogens, that can promote your thryoid to grow. Some foods that are high in goitrogens: broccoli, cabbage, brussels sprouts, cauliflower, radishes, turnips, and more.And then there are several medical risk factors. You are more likely to develop thyroid disease if you've had, or have: thyroid surgery, iodine deficiency, and radioactive iodine treatment or iodine intake, among other other medical treatments and drugs.For more on thyroid functions, diseases and treatments, visit health.about.com. Thanks for watching!