The TSH is thyroid stimulating hormone secreted by pituitary gland. The TSH stimulate thyroid gland to secret T3 and T4 hormones. Its normal levels are 0.4 to4.0. Your higher levels of TSH can be due to tumors in pituitary gland or hypothyroidism. To know about the hypothyroidism, a test for T3 and T4 are required which you have not mentioned. For more details, visit TSH.