2014 Changes in the Electrolyte Profile of Patients having Hypothyroidism Abstract Hypothyroidism is one of the most common forms of thyroid dysfunction. Its effect on electrolytes and certain minerals like calcium, phosphorus, magnesium is not yet clear and the underlying mechanisms for their derangement are not well understood. The objective was to find out the effect of hypothyroidism on certain electrolytes and mineral levels. A total of 110 known cases of hypothyroidism and 110 age and sex match controls were selected. Blood samples were collected from them and T3, T4 and TSH levels were measured. Also calcium, phosphorus, sodium, potassium levels in blood was measured. It was found that magnesium and phosphorus levels were significantly elevated in hypothyroidism cases then the controls. The levels of calcium, sodium and potassium were significantly decreased in cases then controls. It was also found that there was a significant positive correlation between serum TSH values, magnesium and phosphorus levels. At the same time, there was a significant negative correlation between serum TSH values and serum sodium, potassium and calcium levels. Higher the TSH levels, higher will be magnesium and phosphorus levels in blood and lower will be the values of serum calcium, sodium and potassium levels.