Goitre as defined by the Better Health Channel “is an enlargement of the thyroid gland”. The thyroid gland is located below the larynx, at the front of the throat. Controlled by the pituitary gland, the thyroid gland secretes hormones to control the metabolic process, as well as growth and energy expenditure. It is comprised of two lobes that are situated at either side of the trachea and are linked together by an isthmus. As previously mentioned to secrete its hormones the thyroid must be prompted by the pituitary, which releases thyroid-stimulating hormone, to produce thyroxine (T4) and idothyronine (T3). However, without iodine the thyroid is unable to effectively manufacture these proteins. If one’s diet lacks iodine, the pituitary gland continues to send chemical signals to the thyroid gland, but they are not well received. In a vain attempt to obey the demands of the pituitary gland, the thyroid gland enlarges.
There are two classifications of Goitre:-
• Endemic – caused when a whole community is implicated by dietary iodine insufficiencies. This may be caused by a depletion of iodine in the soils in which the harvest is grown, particularly in Tasmania and regions along the Great Dividing Range. Recent evidence also suggests a re-emergence of iodine deficiency in Melbourne, Sydney and other cities of the sort. Endemic goitres, however, tend to be more prominent in Third World countries and are uncommon in First and Second World countries due to the widespread supplementation of iodine.
• Sporadic – only the individual is affected and may be caused by family history, diet, age (40+) and gender (women are more susceptible).
There are two types of Goitre that can be placed in either classification:-
• Diffuse Smooth Goitre – the entire thyroid feels smooth but has enlarged.
• Nodular Goitres – a small lump that evolves into a thyroid. May be divided into two types: Multinodular, whereby many nodules have developed on the thyroid, or Singular, in which a single nodule has developed.
In relation to diet, Goitres are caused due to insufficient iodine (50μg/day), which causes the thyroid to swell as it is trying to produce enough thyroxine and T3. However, Goitres may also be caused by:
• Grave’s Disease – an autoimmune disease which causes the swelling of the thyroid and the production of excess thyroxine. Autoimmune diseases causes the body to produce an antibody that attacks a different part of the body; the thyroid, in this case.
• Thyroid Inflammation (Thyroiditis) – can have various causes; e.g. viral infection.
• Hashimoto’s Thyroiditis (Chronic Lymphocytic Thyroiditis) – causes inflammation of thyroid gland and hypothyroidism.
• Medication – thyroid swelling can be a side effect of certain medications; such as, Lithium.
• Hereditary Factors – thyroid swelling may be inherited. It may swell during certain times in one’s life, e.g. pregnancy and puberty, when excess thyroxine and T3 is being produced.
• Hyperthyroidism – an overactive...