Why is My Menstrual Cycle Getting Longer?

Menstrual cycles typically last between 24 and 38 days with some slight variation between cycles, which is normal. Significant disruptions or irregularities in the length of a period can be as a result of many different factors, ranging from stress and diet, to medical conditions and hormone disorders.

Major changes for months on end, significant changes in flow, or discomfort during a menstrual cycle may require medical intervention to properly address the issue. If you would like to find out why your menstrual cycle might be getting longer, then keep reading. We shall explore potential causes, from hormonal imbalances to factors related to lifestyle, and learn when to seek help.

How Long Does a Menstrual Cycle Last?

A menstrual cycle refers to the length of time between the first day of one’s period, and the day before their next period. This cycle typically lasts between 24 and 38 days, and a variety of factors can impact the duration and consistency of the cycle.

A menstrual cycle consists of four specific phases:

1. Menstruation: This is the duration between the first and last day of a person’s period. During this phase, the uterine lining, or endometrium, is shed if a pregnancy has not occurred. It typically lasts between 3 and 7 days, although some people may experience periods that last longer or shorter than this.
2. The follicular phase: This is the duration following the end of a period. During this time, the endometrium regrows, and simultaneously, As this occurs, several small sacs containing eggs, called antral follicles, expand on the outside of the ovaries until one follicle reaches full maturity. This process typically takes around two weeks.
3. Ovulation: This is the stage in which the mature antral follicle ruptures and the egg contained within  is released. This occurs over the course of about a day and a half.
4. The luteal phase: During this time, the egg travels to the uterus through the fallopian tube. Hormone levels in the uterus increase to support a healthy pregnancy - in the event ir occurs - and they remain high for around two weeks. If no pregnancy occurs during this time, hormone levels gradually decrease until the endometrium begins to shed once again at the start of the next period.

How Does Age Affect Your Menstrual Cycle?

Research done by Harvard University found that people under the age of 20 had an average menstrual cycle length of 30.3 days, while those between the ages of 35 and 39 had an average cycle length of 28.7 days. People in their 40s were found to have slightly shorter cycles, averaging closer to 28 days exactly, while those over 50 years old had cycles averaging nearly 31 days.

Within these age groups, the variance in cycle length was also found to decrease as age increased. Those in their 20s had an average variance of 5.3 days while those in their 30s varying by only 3.8 days. However, after the age of 40, this trend reversed, with people over the age of 50 seeing an average variation of 11.2 days between cycles.

What Causes Your Menstrual Cycle to Change?

Small fluctuations in the length of a menstrual cycle are normal and should not necessarily raise concerns. Variations outside the average range for an individual’s age or extremely inconsistent cycle lengths may indicate an underlying problem. These may require medical intervention or lifestyle changes in order to return to a healthy, consistent cycle.

Hormone Imbalance

A variety of hormones are released during the course of a menstrual cycle, and their concentration varies with each stage of the cycle. Irregularities in the concentration of these hormones can lead to longer menstrual cycles and longer periods in particular. 

Conditions like polycystic ovary syndrome and amenorrhea can lead to irregular periods and may require medical treatment to alleviate symptoms. As well, a variety of thyroid conditions, diabetes, and Cushing’s Syndrome can all potentially disrupt an otherwise consistent menstrual cycle.

Perimenopause

Perimenopause is a transitional phase whereby a person’s ovarian reserve begins to deplete. This causes a shift in menstruation, and a person gradually goes from having regular menstruation into menopause. This transition can take anywhere from several months to several years in some cases.

During this time, ovulation can become less consistent and irregularities in the menstrual cycle become more apparent. This process is often accompanied by other symptoms such as hot flashes, mood changes, and increases in vaginal or bladder infections due to a decline in the production of estrogen. 

Diet

A poor diet, one that does not provide sufficient nutrients necessary to produce the hormones required for a healthy menstrual cycle, can lead to disruptions in the cycle and contribute to an irregular menstrual cycle in many people. This is because hormone levels control the duration of the menstrual cycle. 

A 2022 study exploring the connection between junk food consumption and menstrual abnormalities found that the excessive consumption of junk food can negatively impact the menstrual cycles of women, regardless of their weight.

Stress

There is evidence linking high levels of stress to the production of certain compounds in the brain which suppress hormone production. This might explain why too much stress causes disruptions to an otherwise consistent cycle. 

According to a study on the effects of stress on periods published in 2015 excess stress can have both short-term and long-term effects on the consistency of menstrual cycles, although it is less likely to impact the flow or duration of periods themselves.

Birth Control

Many forms of oral contraceptives limit the body’s ability to produce progestin and estrogen, as a way of preventing ovulation or reducing the likelihood of a fertilized egg implanting on the uterine wall and causing a pregnancy. These forms of medication can in turn also affect how the uterine lining behaves, leading to reduced bleeding during periods, spotting in between periods, and longer stretches of time between periods.

PCOS

Polycystic Ovary Syndrome is a very common condition - the World Health Organization estimates between 8 and 13 percent of reproductive-aged women worldwide are affected by this disorder. In people who have PCOS, many tiny cysts form where follicles would normally develop on the ovaries. These cysts lead to an inability to ovulate normally, causing a variety of potential health conditions if left untreated, and leading to a dramatic reduction in the frequency of periods.

When to See a Doctor

Small fluctuations in a menstrual cycle are not an immediate cause for concern. A period starting as much as an entire week early or late is not necessarily an indication of a problem, particularly if it does not happen often. However, it might be time to get in touch with a professional healthcare provider about what to do next if you experience any of these symptoms,:

• Menstrual cycles that are consistently shorter than 24 days
• Periods that are consistently longer than 7 days
• Periods that are consistently accompanied by severe pain
• Periods that are consistently more than two months apart
• Spotting which consistently occurs between periods
• Consistently experiencing heavy bleeding, requiring a new pad or tampon every hour, during a period

If you have more questions about your menstrual cycle or are seeking options for treatment and consultation, Nevada Fertility Center can help. Our compassionate team of healthcare professionals is here to ease the family planning process.