Irregular or missed periods: What causes them and what do they indicate?

Many people have heard the phrase, "If your period is late, you might be pregnant."
While this statement holds some truth, it's only part of the story. In reality, missed or irregular periods can be caused by a wide range of factors—from harmless conditions to more serious health issues. This article aims to help you better understand the reasons behind missed periods, along with treatment options and answers to common questions.

Understanding Missed Periods: Causes and Treatments

A missed period refers to the absence of menstruation for more than three consecutive months.
There are many possible causes, including:

• Pregnancy
• Menopause
• Breastfeeding
• Hormonal imbalance
• Stress
• Being overweight or underweight
• Certain medications
• Reproductive system disorders

Treatment for missed periods depends on the underlying cause. If the cause is natural (such as pregnancy or menopause), treatment may not be necessary. However, if the cause is due to a medical or lifestyle issue, it may require medical attention and lifestyle adjustments.

Amenorrhea is a condition characterized by the absence of menstrual bleeding when it would normally be expected. If menstruation stops for three months or more, it is classified as amenorrhea. However, if a period is missed for only one or two months, it is generally referred to as delayed menstruation.

This condition is commonly seen in women of reproductive age and is categorized into two types:

1. Primary amenorrhea – when a person has never had a period, typically by age 15–16.
2. Secondary amenorrhea – when a person who previously had regular periods stops menstruating for at least three months.

In general, the characteristics of a normal menstrual period include:

• Color and appearance: Menstrual blood is typically red and does not contain large clots or tissue. Sometimes, it may appear slightly thick or clumpy due to the presence of cervical mucus or ovulation discharge, which is completely normal and harmless.
• Duration: A normal period usually lasts no more than 7 days per cycle and typically occurs once a month. However, in some cases, if a period starts at the beginning of the month, it may occur again at the end of the same month due to the natural cycle.
• Cycle length: The average menstrual cycle is about 28 days, but it can range from 21 to 35 days. Each person should experience a relatively consistent cycle each month. However, irregular periods can be common during the first year of menstruation or around menopause.
• Flow volume: The average menstrual blood loss is around 35 ml per cycle, with a normal upper limit of 80 ml. This is roughly equivalent to using 3–4 sanitary pads per day.

Amenorrhea, or the absence of menstruation, is classified into two main types:

1. Primary Amenorrhea

Primary amenorrhea refers to the condition in which menstruation has never occurred, even after reaching puberty. Girls with this condition are typically 15 years or older and show other signs of puberty (such as breast development or pubic hair), yet they have never had a period, unlike peers of the same age.

Common causes include:

• Congenital abnormalities of the reproductive organs
• Genetic or chromosomal disorders

2. Secondary Amenorrhea

Secondary amenorrhea is the absence of menstruation for three months or more in someone who previously had regular periods. This is the more common type of amenorrhea and can result from various factors, such as:

• Reproductive system disorders
• Hormonal imbalances
• Chronic illnesses
• Pregnancy

Warning Signs of Missed or Irregular Periods

Some women may experience missed or irregular periods occasionally, which can be normal if it only lasts a short time. For example, missing your period for 10 days or even up to a month may be a temporary symptom caused by hormonal imbalances, stress, or insufficient nutrition. These conditions usually do not require concern, and lifestyle changes can often help improve the situation gradually.

However, if your period is absent for more than 3 months, or you frequently experience irregular or missed periods, it is important to monitor your health and consult a doctor to determine the underlying cause. The following symptoms should prompt a visit to the doctor:

• Never having had a period despite being of reproductive age
• Missed periods accompanied by headaches
• Missed periods with lower abdominal pain
• Missed periods with unexplained fatigue
• Previously regular periods that suddenly stop for 3–6 months without pregnancy
• Abnormally heavy bleeding or periods lasting longer than 7 days

Missed Periods May Signal Underlying Medical Conditions

Amenorrhea can also be a warning sign of certain health issues. Common conditions associated with missed or irregular periods include:

Polycystic Ovary Syndrome (PCOS)

PCOS is an endocrine disorder characterized by hormonal imbalances involving estrogen, progesterone, androgens, and insulin. It is one of the most common causes of infertility in women of reproductive age.
Women with PCOS often develop multiple cysts (sometimes called “chocolate cysts”) in their ovaries. These cysts can interfere with normal ovarian function, leading to fewer or irregular periods.

Premature Ovarian Failure (POF)

Premature ovarian failure is the loss of normal ovarian function before the age of 40. Causes include surgical removal of the ovaries, chemotherapy, and radiation therapy in the abdominal or pelvic area. This condition results in early menopause and cessation of menstruation.

Causes of Missed Periods

There are many possible causes of missed periods, including:

1. Pregnancy

Pregnancy is the most common reason for a missed period and is often the first cause people consider. If you are of reproductive age and have had sexual intercourse before your period is missed, pregnancy may be the reason. This is not abnormal and can be initially confirmed with a home pregnancy test using urine or by visiting a doctor for a more accurate test.

2. Accumulated Stress

Stress and anxiety can cause irregular periods or even cause periods to stop for several months. This happens because stress affects hormone secretion related to fertility and menstruation.

3. Body Weight Too High or Too Low

Significant weight gain or loss can cause periods to stop or become irregular. For example, rapid weight loss or starvation can reduce the nutrients needed for hormone production that triggers ovulation. On the other hand, being overweight or obese can cause the body to produce excess estrogen, which affects the menstrual cycle and may cause missed periods.

4. Use of Contraceptive Pills

People who take contraceptive pills may experience lighter, heavier, irregular periods, or no periods at all. Hormonal contraceptives such as progestin-only pills, injections, or hormonal intrauterine devices (IUDs) can cause periods to stop. However, menstruation usually returns to normal after stopping the contraception.

5. Side Effects of Certain Medications

Some medications, such as antidepressants, antipsychotics, thyroid medications, anti-seizure drugs, chemotherapy, or blood pressure medicines, may cause missed or irregular periods.

6. Menopause

Menopause is a natural change that occurs as women age, usually between 45 and 55 years old. Periods start to stop because estrogen levels decline, leading to irregular ovulation. After menopause, menstruation permanently ceases.

When visiting a doctor, the initial diagnosis of missed periods typically involves the following steps:

1. Medical History Review
The doctor will take a detailed medical history, especially related to gynecology and obstetrics. This includes questions about previous pregnancies, contraception methods, history of pelvic exams and cervical cancer screening, as well as a record of past menstrual cycles.

2. Blood Tests
Blood tests are performed to check hormone levels in the body. The doctor will measure hormones related to the menstrual cycle such as prolactin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH). These hormone levels help identify the cause of the missed periods.

3. Ultrasound Examination
The doctor will perform an ultrasound scan of the ovaries and uterus to detect any abnormalities in these organs. Ultrasound uses high-frequency sound waves to create images of internal body structures.

Treatment Approaches

Medication
Amenorrhea can be treated with hormone therapy if it is caused by hormonal imbalances that are not related to serious diseases. To regulate the menstrual cycle, doctors may prescribe hormone medications similar to delay-period pills. Taking these medications regularly at the same time each month for about 6 months can help restore normal periods. After that, the doctor will observe whether menstruation returns naturally without medication.

Surgery Based on Underlying Cause
In some cases, surgery may be necessary. This could be due to congenital adrenal gland problems, underdeveloped ovaries, decreased thyroid hormone production, or uterine fibroids.

Prevention Strategies

• Exercise regularly, but avoid excessive or overly intense workouts as they may disrupt menstrual cycles. Cardio exercise for 20-30 minutes, 3-5 times per week is recommended.
• Eat a balanced diet with all five food groups. Choose healthy fats such as salmon, tuna, or walnuts, and low-fat protein sources like fish or skinless chicken. Include high-fiber foods like vegetables, fruits, and whole grains.
• Manage stress because stress can cause hormonal imbalances affecting menstruation.
• Prioritize good sleep habits. It’s important not only to get enough sleep but also to have a consistent sleep schedule, such as going to bed around 10 p.m. and waking up at 6 a.m., to avoid daytime tiredness.
• Maintain a healthy weight. Being underweight can impair hormone production needed for ovulation, while being overweight can cause missed or irregular periods.

Q: What causes missed periods when not pregnant?
A: Lifestyle factors such as stress, poor nutrition, and excessive caffeine intake can cause irregular or missed periods. Additionally, intense exercise and working night shifts can also affect the menstrual cycle.

Q: How long can a period be delayed?
A: Normally, menstrual cycles occur every 21 to 35 days. However, sometimes periods may come earlier or later by about 3 to 7 days. The timing of periods can be influenced by many factors that affect cycle regularity.

Amenorrhea or irregular menstruation is a condition that can affect any woman. The causes can be natural, such as pregnancy or menopause, or due to abnormalities like accumulated stress, hormonal imbalances, or various illnesses. Irregular or missed periods are often a contributing factor to infertility.

If you experience abnormal symptoms such as fever, vomiting, missed periods, or periods lasting longer than 7 days, you should see a doctor promptly to diagnose the cause and find appropriate treatment. For further inquiries, you can contact us via Line: @beyondivf

References

Amenorrhea – Symptoms and causes – Mayo Clinic. (2023, February 9). Mayo Clinic. https://www.mayoclinic.org/dis...

Professional, C. C. M. (2023, March 3). Amenorrhea. Cleveland Clinic. https://my.clevelandclinic.org...

Amenorrhea. (2017, January 31). https://www.nichd.nih.gov/heal..." class="redactor-autoparser-object">https://www.nichd.nih.gov/.&nb...