The foggy brain syndrome is another symptom of PMS. You feel though you’re slogging through mud, while everyone else is jogging along at a brisk clip. You just can’t seem to think sharply, remember, or perform well.

For a long time, the medical establishment and even many women discounted this symptom, in part because “fuzzy thinking” a subjective assessment of how any given individual functions. However, fuzzy thinking can also be a demonstrated effect of aging. Studies on menopausal women aged forty to sixty have shown that their memory and cognitive abilities improved after they underwent hormone replacement therapy. This has led researchers to begin accepting the idea that cognitive impairment may be real in many women and that it is somehow related to estrogen levels. Researchers think the findings on fuzzy thinking in older women may be applicable women with PMS.