More than half of women over the age of 50 have hair loss. In a study published last week in the journal Menopause, researchers in Thailand measured the hormone levels of almost 200 postmenopausal women. They also analyzed the density of hair in the middle of the scalp, where female pattern hair loss generally begins. They found that over 52 percent of the women had female pattern hair loss. Low self-esteem accompanied the hair loss in 60 percent of those women. The researchers also believe the declining estrogen levels in these postmenopausal women was the likely cause for the hair loss.