Goitre can also result from cyanide poisoning, which is particularly common in tropical countries where people eat the cyanide-rich cassava root as the staple food. Sarcoidosis
Amyloidosis
Hydatidiform mole
Cysts
Acromegaly
Pendred syndrome

Diagnosis
Goitre may be diagnosed via a thyroid function test in an individual suspected of having it. Types
A goitre may be classified either as nodular or diffuse. Nodular goitres are either of one nodule (uninodular) or of multiple nodules (multinodular). Growth pattern
Uninodular goitre: one thyroid nodule; can be either inactive, or active (toxic) – autonomously producing thyroid hormone. Multinodular goitre: multiple nodules; can likewise be inactive or toxic, the latter is called toxic multinodular goitre and associated with hyperthyroidism. These nodules grow up at varying rates and secrete thyroid hormone autonomously, thereby suppressing TSH-dependent growth and function in the rest of gland. Inactive nodules in the same goitre can be malignant. Thyroid cancer is identified in 13.7% of the patients operated for multinodular goitre. Diffuse goitre: the whole thyroid appearing to be enlarged due to hyperplasia.Size
Class I: the goitre in normal posture of the head cannot be seen; it is only found by palpation. Class II: the goitre is palpable and can be easily seen. Class III: the goitre is very large and is retrosternal (partially or totally lying below the sternum), pressure results in compression marks. Treatment
Goitre is treated according to the cause. If the thyroid gland is producing an excess of thyroid hormones (T3 and T4), radioactive iodine is given to the patient to shrink the gland.
A goitre, or goiter, is a swelling in the neck resulting from an enlarged thyroid gland. A goitre can be associated with a thyroid that is not functioning properly. Worldwide, over 90% of goitre cases are caused by iodine deficiency. The term is from the Latin gutturia, meaning throat. Most goitres are not cancerous (benign), though they may be potentially harmful. Signs and symptoms
A goitre can present as a palpable or visible enlargement of the thyroid gland at the base of the neck. A goitre, if associated with hypothyroidism or hyperthyroidism, may be present with symptoms of the underlying disorder. For hyperthyroidism, the most common symptoms are associated with adrenergic stimulation: tachycardia (increased heart rate), palpitations, nervousness, tremor, increased blood pressure and heat intolerance. Clinical manifestations are often related to hypermetabolism, (increased metabolism), excessive thyroid hormone, an increase in oxygen consumption, metabolic changes in protein metabolism, immunologic stimulation of diffuse goitre, and ocular changes (exophthalmos). Hypothyroid people commonly have poor appetite, cold intolerance, constipation, lethargy and may undergo weight gain. However, these symptoms are often non-specific and make diagnosis difficult.According to the WHO classification of goitre by palpation, the severity of goitre is currently graded as grade 0, grade 1, grade 2. Causes
Worldwide, the most common cause for goitre is iodine deficiency, commonly seen in countries that scarcely use iodized salt. Selenium deficiency is also considered a contributing factor. In countries that use iodized salt, Hashimotos thyroiditis is the most common cause.