Development Of The Female Body
Life Stages of Being A Woman: From Puberty to Menopause

Health Topics

Just one long hormone ride!

Endocrine System: Hormones and their functions.

How The Female Body Develops


How does a woman's body change over a lifetime?
Old Age

How Does A Woman's Body Change Over A Lifetime?

Over the course of a lifetime the female body goes through many changes. Primarily those changes occur during puberty, pregnancy and menopause and are controlled by hormone fluctuations. Hormones are a chemical substance produced mainly by the pituitary glands. They are little chemical messengers that travel through the bloodstream and issue orders to cells and organs throughout the body. They regulate how fast we grow, when our sexual organs should develop and when our body is developed enough to start reproducing. They also have other tasks such as regulating the composition of our blood, and some, like insulin, are necessary in order to stay alive. The discovery of hormones is only very recent, they were first spotted in 1902. Since then scientists have discovered ways to artificially produce (synthesize) hormones in laboratories. These synthesized products can trick the body into believing that they are the real thing - synthetic hormones are commonly used to treat people with diabetes, to offer relief to women going through menopause (estrogen replacement therapy, ERT) and to prevent pregnancy (the contraceptive pill). Hormones are classified in various ways. They may be classified according to where they are produced - such as ovarian and adrenal hormones - or according to the function they affect - such as the sex hormones (HCG, human chorionic gonadotropin; FSH follicle-stimulating hormone and LH, luteinizing hormone) or growth hormones (oxytocin, prolactin and somatotropin). Hormones levels fluctuate at different times of our life, depending on the physical requirements placed on the body.



Changes In The Female Body During Puberty

Hips widen to prepare for childbirth.
Pubic and underarm hair develop.
Sweat glands develop and we start sweating.
Skin becomes oilier, acne can occur.
Fat appears on the hips, bottom, thighs and breasts.
The nipples become darker and more prominent in preparation for breastfeeding.
The womb and ovaries develop and menstruation starts by the age of 12.5.

Puberty is the time a girl reaches sexual maturity. It begins much earlier in girls than boys - it starts about the age of 9 or 10 (between 12 and 14 for boys) and lasts roughly 5 years. During puberty the girl experiences a growth spurt and a period of rapid weight gain. Most girls reach their mature height soon after their first period (menarche) which occur about 3 or 4 years after the start of puberty. The average age for menarche in the United States today is 12.5 years. Around this time estrogen levels rise causing the growth centers at the end of the bones of the body to close, thus ending growth. The increase in estrogen also causes deposits of fat to gather on the breasts, hips, thighs, buttocks and upper arms, and so the girl develops the characteristic body shape of a woman. This increase in fat makes the girl's muscles appear less pronounced - boys in comparison have a rush of androgen hormone which makes their muscles more defined. Influenced by the rush of hormones, the womb becomes bigger, the vagina becomes longer and the lips of the vulva become more pronounced. Puberty is also when secondary characteristics develop. The girl develops underarm hair, pubic hair and her sweat glands enlarge so she perspires more. Her breasts gradually get larger although it may be noted that one breast grows faster than the other.

Some teenagers worry that they are developing too quickly (precocious puberty) but most often they worry about developing too late (delayed puberty). Delayed puberty is caused by late hormone production and is rarely any cause for concern. For most, the teenager simply need to be reassured that their body is developing at the right pace. If however there is no sign of puberty change by the age of 16 (total puberty failure) it is important to consult a doctor to rule out tumors or any serious underlying diseases. Total puberty failure is more common in boys than girls and it usually responds to hormone therapy.

Related Questions
When should my periods start?
What can cause changes in my cycle?

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Recommended health screenings for women.


Common Problems That Affect Menstrual Cycles

Polycystic ovary syndrome: a condition caused by a hormone imbalance.
Ovarian cysts: blisters on the ovaries.
Uterine fibroids: benign (non-cancerous) tumors on or in the womb.
Endometriosis: benign growths that can spread throughout the reproductive system.

Other Period Problems
Heavy periods.
Painful periods.
Missed periods.
Premenstrual dysphoric disorder (severe PMS).
Toxic shock syndrome.
Reproductive disorders.

A girl starts to menstruate (discharge menstrual blood) more or less every month after the onset of menarche; and continues to do so until she is either pregnant or reaches menopause. After the birth of a baby, the menstrual cycle recommences. When menopause is reached, periods completely stop and pregnancy is no longer possible. Once a girl reaches menarche, the hypothalamus in the brain sends a message to her pituitary gland to produce FSH and LH hormones. These hormones then travel to the ovaries and instruct them to start producing estrogen and progesterone. It is these hormones that tell the body when to initiate the menstrual cycle. Conversely when these hormones dwindle later in life this informs the body to stop menstruating at menopause.

The function of the menstrual cycle is to prepare the body for conceiving a baby. Every month, the lining of the womb (uterus) builds up and prepares to support a fertilized egg and the growth of a baby. If no egg is fertilized the cycle ends and the uterus wall breaks down and is shed (menstrual flow). Many women experience premenstrual syndrome (PMS) in the days leading up to a period. Symptoms include a bloated stomach, headaches, painful breasts, irritability, mood swings and mild depression. The symptoms usually disappear after the period starts. The average menstrual cycle is about 28 days, but anywhere between 21 and 38 days is common. There are many conditions and circumstances that affect the menstrual cycle such as illness, emotional stress and an abrupt change in temperature.



What Can Go Wrong
Bleeding during pregnancy.
Fibroids and pregnancy.
Heart problems in pregnant women.
Raised blood pressure in pregnancy.
Ovarian cysts in pregnancy.
Gestational diabetes.
Cervical cancer in pregnancy.
Pregnancy complications including varicose veins, back pain and food cravings.

Related Issues

Infertility in women.
Postpartum depression.

Between the ages of 20 and 40, many women will experience at least one pregnancy. While pregnancy can be a wonderful emotional experience, it places enormous stress on the mother's body. For this reason, the stronger and healthier she is before pregnancy, the less likely she is to experience pregnancy complications. For 9 months (about 40 weeks) the woman's body will undergo a series of changes and sensations as she nurtures her baby to growth and her body prepares for childbirth. Like most other events, hormones are the messengers which tell the body how to change, adapt and develop.

First Trimester
In the first 12 weeks (known as the first trimester), the physical signs can be missed or mistaken for PMS. The earliest signs of pregnancy are usually a missed period, morning sickness, tender breasts and fatigue. (See also, what are the signs of pregnancy before a missed period?). These symptoms all reflect the hormone changes in the body. Within 5 to 7 days of conception, HCG hormone levels appear in the blood and urine, detection of these hormones forms the basis of most pregnancy tests. Progesterone and estrogen levels gradually rise and blood supply to the pelvis increases so it starts to change shape.

Second Trimester
By the second trimester the abdomen is larger and the size and shape of the womb has completely changed. Increasing levels of estrogen stimulate the muscles of the uterus to grow in preparation for the contractions of labor. It also helps to develop the milk glands in the breasts in preparation for breastfeeding and the ligaments and joints relax to accommodate the growing baby. The heart-rate of the mother increases as does the volume of blood being pumped by the heart. This allows the fetus to develop properly. However it can put a strain on women with a pre-existing heart problem or high blood pressure. Raised levels of HCG can induce gestational diabetes in susceptible women.

Third Trimester
During the third trimester, stretch marks may appear as the skin is pulled over the ever-expanding tummy. The nipples enlarge and the woman gains weight rapidly. The baby rotates around week 36 so that he is head down, ready for birth. This is called 'lightening' and usually relieves pressure on the upper abdomen and breathing, although it can increase pressure on the bladder causing vaginal discharge. Raised progesterone levels help to prevent uterine contractions and premature labor until the baby is near to its due date.

Top Signs of Perimenopause

Hot Flushes
Disturbed sleep
Heart Palpitations
Lack of concentration
Skin dryness
Vaginal itching
Mood Swings



Perimenopausal Issues

Pregnancy after 35.
Genetic testing during pregnancy.
How can I increase my fertility naturally?
IVF Treatment.
How does egg donation work?
Dangers of stress.

Questions You Might Want Answered

What is considered middle aged?
Why am I so tired all the time?
Are there any home tests for diabetes?
For more, see womens health questions.
For skin issues, see skin care questions.

Perimenopause is the transition phase all women make towards menopause. It is a natural shift from regular monthly menstrual cycles towards permanent cessation and commonly begins in the early 40s. When we are born, women have all the eggs (oocytes) they will ever have - in fact, on average we are born with 2 million, and during our reproductive years about 400 will mature and be released (one a month). As time progresses these eggs start to shrivel, which is why pregnancy after 35 becomes more difficult. The quality of the eggs are not as good and the risk of birth defects is higher. It is also why older women who wish to conceive do better with egg donation (from a younger woman). As we approach menopause the level of estrogen in our body falls - this 'informs' the reproductive system to gradually shut down. Periods become irregular, there may be mood swings and difficulties sleeping. Conversely FSH and LH levels rise, this indicates that the ovaries are starting to fail. See our article, how menopause affects the body.



Menopausal Issues

Low libido in menopause.
Hot flashes.
Menopause skin changes.
Menopausal depression.
Menopause hair loss.
Weight gain in menopause.

Common Problems That Can Develop

Osteoporosis: Losing bone density.
Fibromyalgia pain: All over muscle aches.
Arthritis: Aching bones and joints.
Angina: Early signs of heart problems.
Breast Cancer: Check the symptoms.
Effects of Depression: Recognize the signs.

When periods have ceased for 12 months consecutively, a woman is said to have reached menopause. Menopause typically occurs in women between the ages of 45 and 55. If a woman starts menopause before this (usually due to a hysterectomy and removal of the ovaries) she is said to have entered premature menopause. The hormone balance is her body shifts significantly, and this can cause menopause symptoms (not unlike pregnancy symptoms) including hot flashes, mood swings, headaches and sleeping problems. Once the hormones 'settle down' things should improve, however many women find the transition so debilitating they choose to take ERT to minimize the effects. The declining levels of estrogen however can be a god-send for women who have suffered from conditions associated with excess estrogen in their reproductive years - many conditions like PCOS, endometriosis, fibroids and ovarian cysts improve or even disappear after menopause. However, estrogen has protective attributes, and declining levels expose women to other risks, including osteoporosis and heart attacks. Most women find their body shape gradually begins to change after they reach their mid 40s or 50s. Lower levels of estrogen can result in redistribution of body fat. Gradually the tummy and waist become larger, while the legs and arms become thinner. Although you may not weigh particularly more than you used to, the new shape may necessitate an increase in dress size, which mentally is registered as weight gain.


The postmenopause period begins once a woman reaches menopause and continues for the rest of her natural life. As menopause hormone fluctuations settle, hot flashes become milder or disappear, mood swings reduce and energy levels return. Emotionally and physically a woman moves into a new phase of her life, and typically she can expect to live a full third of her life after menopause. 10 to 20 percent of postmenopausal women will however experience ongoing issues related to reduced estrogen including vaginal atrophy, urinary tract infections and weight gain. Bones become more brittle (signs of osteoporosis) and so you need to have a bone density scan every couple of years.



What Can Go Wrong

Bone and joint problems
Back problems
Chest problems
Heart Attacks
Heart Disease
Strokes in women
Heart Failure

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The average American women lives until the age of 80 and they are likely to survive their male partner by 5 years. Currently there are about 21 million women aged over 65 living in the U.S. compared to 15 million men. Since the 1950s the number of women living beyond the age of 65 has more than tripled it is estimated that there will be 48 million women by 2040. Considering that you are likely to live longer than any generation before you, it is worth looking after your body so that your lifestyle quality in your old age remains good. After all, what fun is it turning 80 if you can't walk further than the TV because of angina or you can't bend down and pick something up because of arthritis? The best way to ensure some quality of life at an advanced age is to look after your health in your middle years (or earlier). This means, not smoking, maintaining a healthy body weight, drinking alcohol in moderation and taking regular physical exercise. Some financial planning is also advisable. As fewer old women have a spouse to rely on as a primary caregiver, they are more reliant on other informal (unpaid) caregivers like family members and friends. They also have a greater need for paid care services like nursing homes.

Related Articles

Female Reproductive System: Diagrams of organs and how pregnancy happens.
Muscles Of The Body: How they work and what they do.

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