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Atypical manifestations of hypothyroidism

Thyroid hormone can directly influence every cell in the human body.Diagnostic confusion may occur when the functional derangement of one body system dominates the clinical picture.
Following are the common manifestations of hypothyroidism
Weight gain
Cold intolerance
Puffy face
Pedal edema
Atypical manifestation of hypothyroidism are not so rare.So high index of suspicion is necessary to diagnose the situation, this is very important because the disease is completely reversible and the treatment is cheap.When there is unexplained clinical conditions such as neuropsyhiatric, non responding cardiac,locomotor, gastrointestinal problems and in PUO(pyrexia of unknown origin) rule out thyroid dysfunction (can be hypothyroidism or hyperthyroidism)  including auto immune status.
Psychiatric manifestations of hypothyroidism
Psychiatric symptoms are common in both overt hypothyroidism as well as in subclinical hypothyroidism.Depression may be the first or sometimes the only clinical manifestation in hypothyroidism.Hypothyroidism may manifest as a variety of other neuropsychiatric symptoms which include
Mood disorders
Bipolar disease
Visual and auditory hallucinations
Cognitive dysfunction
Impaired concentration
Decline in intelligence
Memory disturbance
Cognitive dysfunction are more pronounced in elderly, hence it should be considered as a reversible cause of dementia.
Dermatological manifestations of hypothyroidism 
Sometimes dermatological manifestations are initial manifestation of hypothyroidism.
This may present as pruritus or urticaria .Symptoms may continue even after correction of hypothyroidism.
Muskuloskeletal manifestations of hypothyroidism
Arthralgia, arthritis
If there Is predominant small joint involvement of hands it mimick rheumatoid arthritis
Hypothyroidism can  also involve large joints producing myxedematous arthropathy is characterized by synovial thickening, ligamentous laxity and  effusion
Hyperuricemia may contribute to joint pathology.
Joint involvement is more common when the hypothyroidism is of autoimmune etiology
Other presentations are 
Association with other endocrine dysfunction.
Hyponatremia  is seen in 10 % of hypothyroid patients.Mechanism of hyponatremia in hypothyroidism are due to
Reduction in GFR, impairement of water excretion
Inappropriate release of ADH
When there is unexplained reduction in serum sodium, always evaluate thyroid function
Hyperprolactinemia,headache may be a rare manifestation of hypothyroidism.It may be due to increased TRH production,thyrotrope  hyperplasia  and pituitary  enlargement.Normalization of symptoms occur with thyroid replacement.