There are many things that may cause a woman to have a light menstrual period. Among the most common are hormonal changes. These changes can include those that occur in the years leading up to menopause as well as those related to occasional fluctuations in a woman’s body. In some cases, birth control pills or eating disorders may lead to lighter-than-normal periods as well. Additionally, a woman may have a lighter period because of stress, which may be of a physical or emotional nature.
Hormonal changes are frequent causes of light menstrual periods. For example, a woman may experience significant hormonal changes during perimenopause, which is the stage of a woman's life that leads up to menopause. In many cases, a woman’s periods become irregular during this time and the interval between periods may increase. A lighter flow often accompanies these changes, and eventually, the woman ceases to menstruate altogether. Sometimes, however, hormonal fluctuations that cause a lighter period are temporary in nature.
Birth control pills may also cause light menstruation. The interesting part about birth control use and vaginal bleeding is that many women incorrectly assume they are menstruating while they are taking birth control pills. In reality, however, birth control pills usually prevent ovulation and true menstruation. When women bleed vaginally while taking the inactive pills in a birth control pack, they are usually experiencing withdrawal bleeding as the result of days without the hormones in the birth control pills. This withdrawal bleeding is often lighter than a normal menstrual period and may be shorter in duration as well.
Sometimes eating disorders are at fault when a woman has light menstruation. Poor nutrition and extremely low body weight can interfere with the production of hormones required for a normal menstrual cycle. The result may be a lighter-than-normal menstrual period. In fact, some people who struggle with eating disorders may miss menstrual periods altogether. Athletes who push their bodies to extremes may have menstrual cycle changes as well.
In many cases, stress also contributes to light menstruation. Stress may interfere with the production and release of hormones that are critical for normal menstruation. This may cause a woman to have lighter periods, short periods, or irregular cycles. Both physical and emotional stress may have this effect.
There are also some medical conditions that may cause a woman to have light menstruation. For example, a woman may have a light period in relation to an autoimmune condition or problems with her thyroid gland. Additionally, a condition called polycystic ovary syndrome may cause lighter menstrual periods.