Yes, TSH levels in an individual may fluctuate due to a number of factors. TSH levels may show marked variation depending on the time when they are measured. So, daytime testing is usually preferred. Elevated TSH levels have also been observed with aging and during the cold winter months. Total T3 & T4 concentrations are also altered by changes in thyroid binding protein levels. In such cases, levels of free T4, free T3 may be advised.