Autoimmune Hypothyroidism may be associated with Goiter (Hashimoto disease) or in later stages Atrophic Thyroiditis. The autoimmune process gradually reduces thyroid function with a phase of compensation when normal thyroid hormone levels are maintained by a rise in TSH. This is called Subclinical hypothyroidism. The incidence rate of hypothyroidism is 4 per 1000 women and 1 per 1000 men. The mean age at diagnosis is 60 years and the prevalence of overt hypothyroidism increases with age. Presence of TPO antibodies with subclinical hypothyroidism increases the risk by 4% of developing clinical hypothyroidism.