As progesterone production increases, your blood sugar levels may rise. Production of these two hormones varies throughout the menstrual cycle and doesn't always occur simultaneously or to the same degree. The majority of women who monitor their blood sugar levels don't notice a significant change in their blood sugar levels. Women who do experience fluctuations may be influenced by other factors that can accompany menstruation, such as variations in their diet or level of physical activity. It's generally during the third week of your menstrual cycle, at the time of ovulation, that estrogen and progesterone levels are highest and you're most likely to experience changes in your blood sugar.
Premenstrual syndrome is a condition that occurs in some women about a week before menstruation.
Symptoms include mood swings, tender breasts, bloating, lethargy, food cravings and lack of concentration. Giving in to cravings for carbohydrates and fats also can make blood sugar control more difficult. Note any symptoms you experience before menstruation, such as bloating, irritability, fatigue, cramps, weight gain or food cravings. Also record the day your period begins and the day it ends. Look for patterns in your blood sugar levels, especially the week before your period.