Stages Of Menstural Cycle
Introduction
Each month during the years between puberty and menopause, a woman’s body goes through a number of changes to get it ready for a possible pregnancy. This series of hormone-driven events is called the menstrual cycle.
During each menstrual cycle, an egg develops and is released from the ovaries. The lining of the uterus builds up. If a pregnancy doesn’t happen, the uterine lining sheds during a menstrual period. Then the cycle starts again.
A woman’s menstrual cycle is divided into four phases:
menstrual phase
follicular phase
ovulation phase
luteal phase
The length of each phase can differ from woman to woman, and it can change over time.
Menstrual phase
The menstrual phase is the first stage of the menstrual cycle. It’s also when you get your period.
This phase starts when an egg from the previous cycle isn’t fertilized. Because pregnancy hasn’t taken place, levels of the hormones estrogen and progesterone drop.
The thickened lining of your uterus, which would support a pregnancy, is no longer needed, so it sheds through your vagina. During your period, you release a combination of blood, mucus, and tissue from your uterus.
You may have period symptoms like these:
cramps (try these home remedies)
tender breasts
bloating
mood swings
irritability
headaches
tiredness
low back pain
On average, women are in the menstrual phase of their cycle for 3 to 7 days. Some women have longer periods than others.
Follicular phase
The follicular phase starts on the first day of your period (so there is some overlap with the menstrual phase) and ends when you ovulate.
It starts when the hypothalamus sends a signal to your pituitary gland to release follicle-stimulating hormone (FSH). This hormone stimulates your ovaries to produce around 5 to 20 small sacs called follicles. Each follicle contains an immature egg.
Only the healthiest egg will eventually mature. (On rare occasions, a woman may have two eggs mature.) The rest of the follicles will be reabsorbed into your body.
The maturing follicle sets off a surge in estrogen that thickens the lining of your uterus. This creates a nutrient-rich environment for an embryo to grow.
The average follicular phaseTrusted Source lasts for about 16 days. It can range from 11 to 27 days, depending on your cycle.
Ovulation phase
Rising estrogen levels during the follicular phase trigger your pituitary gland to release luteinizing hormone (LH). This is what starts the process of ovulation.
Ovulation is when your ovary releases a mature egg. The egg travels down the fallopian tube toward the uterus to be fertilized by sperm.
The ovulation phase is the only time during your menstrual cycle when you can get pregnant. You can tell that you’re ovulating by symptoms like these:
A slight rise in basal body temperature
Thicker discharge that has the texture of egg whites
Ovulation happens at around day 14 if you have a 28-day cycle — right in the middle of your menstrual cycle. It lasts about 24 hours. After a day, the egg will die or dissolve if it isn’t fertilized.
After the follicle releases its egg, it changes into the corpus luteum. This structure releases hormones, mainly progesterone and some estrogen. The rise in hormones keeps your uterine lining thick and ready for a fertilized egg to implant.
If you do get pregnant, your body will produce human chorionic gonadotropin (hCG). This is the hormone pregnancy tests detect. It helps maintain the corpus luteum and keeps the uterine lining thick.
If you don’t get pregnant, the corpus luteum will shrink away and be resorbed. This leads to decreased levels of estrogen and progesterone, which causes the onset of your period. The uterine lining will shed during your period.
During this phase, if you don’t get pregnant, you may experience symptoms of premenstrual syndrome (PMS). These include:
- bloating
- breast swelling, pain, or tenderness
- mood changes
- headache
- weight gain
- changes in sexual desire
- food cravings
- trouble sleeping
The luteal phase lasts for 11 to 17 days. The average lengthTrusted Source is 14 days.
Every woman’s menstrual cycle is different. Some women get their period at the same time each month. Others are more irregular. Some women bleed more heavily or for a longer number of days than others.
Your menstrual cycle can also change during certain times of your life. For example, it can get more irregular as you get close to menopause.
One way to find out if you’re having any issues with your menstrual cycle is to track your periods. Write down when they start and end. Also record any changes to the amount or number of days you bleed, and whether you have spotting between periods.
Any of these things can alter your menstrual cycle:
- Birth control. The birth control pill may make your periods shorter and lighter. While on some pills, you won’t get a period at all.
- Pregnancy. Your periods should stop during pregnancy. Missed periods are one of the most obvious first signs that you’re pregnant.
- Polycystic ovary syndrome (PCOS). This hormonal imbalance prevents an egg from developing normally in the ovaries. PCOS causes irregular menstrual cycles and missed periods.
- Uterine fibroids. These noncancerous growths in your uterus can make your periods longer and heavier than usual.
- Eating disorders. Anorexia, bulimia, and other eating disorders can disrupt your menstrual cycle and make your periods stop.
Here are a few signs of a problem with your menstrual cycle:
- You’ve skipped periods, or your periods have stopped entirely.
- Your periods are irregular.
- You bleed for more than seven days.
- Your periods are less than 21 days or more than 35 days apart.
- You bleed between periods (heavier than spotting).
If you have these or other problems with your menstrual cycle or periods, talk to your healthcare provider.
Every woman’s menstrual cycle is different. What’s normal for you might not be normal for someone else.
It’s important to get familiar with your cycle — including when you get your periods and how long they last. Be alert for any changes, and report them to your healthcare provider.
Why Is My Period Late: 8 Possible Reasons
Worried about a late period, but know you’re not pregnant? Missed or late periods happen for many reasons other than pregnancy. Common causes can range from hormonal imbalances to serious medical conditions.
There are also two times in a woman’s life when it’s totally normal for her period to be irregular: when it first begins, and when menopause starts. As your body goes through the transition, your normal cycle can become irregular.
Most women who haven’t reached menopause usually have a period every 28 days. However, a healthy menstrual cycle can range from every 21 to 35 days. If your period doesn’t fall within these ranges, it could be because of one of the following reasons.
Stress can throw off your hormones, change your daily routine, and even affect the part of your brain responsible for regulating your period — your hypothalamus. Over time, stress can lead to illness or sudden weight gain or loss, all of which can impact your cycle.
If you think stress might be throwing off your period, try practicing relaxation techniques and making lifestyle changes. Adding more exercise to your regimen may help get you back on track.
Women with eating disorders, such as anorexia nervosa or bulimia, may experience missed periods. Weighing 10 percent below what’s considered a normal range for your height can change the way your body functions and stop ovulation. Getting treatment for your eating disorder and putting on weight in a healthy way can return your cycle to normal. Women who participate in extreme exercise such as marathons may stop their periods as well.
Just as low body weight can cause hormonal changes, so can being overweight. Your doctor will recommend a diet and exercise plan if they determine that obesity is a factor in your late or missed periods.
4. Polycystic ovary syndrome (PCOS)
Polycystic ovary syndrome (PCOS) is a condition that causes your body to produce more of the male hormone androgen. Cysts form on the ovaries as a result of this hormone imbalance. This can make ovulation irregular or stop it altogether.
Other hormones, such as insulin, can also get out of balance. This is due to insulin resistance, which is associated with PCOS. Treatment for PCOS focuses on relieving symptoms. Your doctor may prescribe birth control or other medication to help regulate your cycle.
You may experience a change in your cycle when you go on or off birth control. Birth control pills contain the hormones estrogen and progestin, which prevent your ovaries from releasing eggs. It can take up to six months for your cycle to become consistent again after stopping the pill. Other types of contraceptives that are implanted or injected can cause missed periods as well.
Chronic diseases such as diabetes and celiac disease also can affect your menstrual cycle. Changes in blood sugar are linked to hormonal changes, so even though it’s rare, poorly controlled diabetes could cause your period to be irregular.
Celiac disease causes inflammation that can lead to damage in your small intestine, which may prevent your body from absorbing key nutrients. This can cause late or missed periods.
Most women begin menopause between ages 45 to 55. Women who develop symptoms around age 40 or earlier are considered to have early peri-menopause. This means your egg supply is winding down, and the result will be missed periods and eventually the end of menstruation.
An overactive or underactive thyroid gland could also be the cause of late or missed periods. The thyroid regulates your body’s metabolism, so hormone levels can be affected as well. Thyroid issues can usually be treated with medication. After treatment, your period will likely return to normal.
Your doctor can properly diagnose the reason for your late or missed period and discuss your treatment options. Keep a record of changes in your cycle as well as other health changes to show your doctor. This will help them make a diagnosis.
If you have the following symptoms, contact a doctor right away:
unusually heavy bleeding
severe pain
bleeding that lasts longer than seven days
bleeding after you’ve already entered menopause and had not periods for a year
If you don’t already have an OBGYN, you can browse doctors in your area through the Healthline FindCare tool.