What Are the Causes of Period Spotting?

In a regular menstrual period, bleeding only happens in the first week of the menstrual cycle. This bleeding lasts anywhere from three to five days. Some women experience a light bleeding outside of this time; this is called "spotting." Spotting can occur anytime outside of the normal three-to five-day bleeding, and can be caused by many medical conditions and medications.

Regular Menstrual Cycle

• A normal menstrual cycle lasts anywhere from 21 to 45 days, with menstrual bleeding occurring between three to five days. During a normal menstrual cycle, the hormone estrogen increases to ready the ovaries for egg production. As this process takes place, the endometrial lining within the uterus thickens in anticipation of conception. When conception doesn't occur, the lining breaks apart and sheds along with blood as menstrual flow. When any part of this normal cycle is disrupted, it will cause heavy or lighter bleeding, painful periods, in-between bleeding (spotting), and shorter or longer cycles.

Combination Birth-Control Pills

• Combination birth-control pills are contraceptive pills that use a combination of the hormones progestin and estrogen to prevent pregnancy. Levels of estrogen in these pills are usually lower than what the body normally produces. This low dose of estrogen can cause ovulation to halt, although the uterine lining still thickens. This causes the lining to break down in small amounts at different times. Usually light amounts of bleeding accompany the lining as it breaks down. This light bleeding can happen at anytime within the menstrual cycle.

Perimenopause

• Perimenopause is also known as menopause transition. This is the stage that occurs about two years before the onset of menopause. During this time estrogen levels gradually decrease causing periods to become lighter and more spaced out. As hormonal levels fluctuate during this time, spotting is often reported. In addition, during menopause some women report spotting. This is a result of estrogen being depleted, causing the vagina's natural moisture to decrease. This leaves the vagina dry, which makes it more prone to injury and slight spotting after intercourse.

Polycystic Ovarian Syndrome

• According to The International Council on Infertility Information Dissemination, Polycystic Ovarian Syndrome (PCOS), is a medical condition that affects 5 percent to 10 percent of the U.S. female population. PCOS causes androgens (male hormones) to become more dominant over female hormones, including estrogen. Often times women with PCOS don't ovulate but still have monthly menstrual cycles. The hormonal fluctuations with this condition can be so erratic that menstrual cycles are often hard to predict and are absent for months. The hormone estrogen can be signaled at anytime during this condition, causing spotting or light bleeding between periods.

Endometriosis

• During a normal menstrual cycle, the uterine lining builds up within the uterus, but with endometriosis this lining can build up within any part of the body. It mainly forms on the abdomen, intestines, ovaries and uterus. When the lining begins to break down and shed during menstruation, the tissue growing outside of the uterus behaves in the same way. Bleeding can happen at anytime with this condition and spotting is one of the classic signs of endometriosis.