coynemedical period

What is a normal period, a heavy period and Menorrhagia?


First, here is an over-view of the female reproductive cycle to give you a brief background.

The primary function of the female reproductive system is to produce eggs (ova) to be fertilised, and to provide the environment to allow a baby to develop. Females are born with immature follicles which lie dormant in the ovaries from birth until puberty. Activity is controlled by hormones which are released by both the brain and the ovaries. The cyclical release of these hormones gives women their reproductive or menstrual cycle. The length of the cycle is usually between 24-35 days and the rising hormone levels lead to the maturation of several ovarian follicles per month; usually only one matures and is released. This key event is known as ovulation and typically occurs around day 14 of a 28 day cycle. The egg is developed and matured, preparing for fertilisation with the male sperm. At the same time the lining of the womb (uterus) is prepared to receive a fertilised egg. If a fertilised egg is not implanted into the uterus, the lining of the uterus is shed and is expelled from the body and this is known as having a period, or menstruation. Day one of a period is known as day one of the menstrual cycle.

There are five main hormones that control the reproductive cycle. Three are produced in the brain, while the other two are made in the ovaries:

Gonadotrophin-releasing hormone (GnRH) is made by a part of the brain called the hypothalamus, this then travels to another part of the brain called the pituitary where it controls the release of follicle-stimulating hormone (FSH) and luteinising hormone (LH).

FSH is carried by the bloodstream to the ovaries where it stimulates the immature eggs (ova) to start growing.

LH triggers ovulation and stimulates the corpus luteum (which is the remains of the ovarian follicle that has released a mature egg) to release oestrogen and progesterone which encourage the growth and maturation of the lining of the uterus.

Oestrogen is produced by the growing egg and by the corpus luteum. Before ovulation, there are moderate amounts of oestrogen and this helps to control the levels of GnRH, FSH and LH and this helps to prevent the development of too many eggs. Eventually one mature egg outgrows the rest. While this is happening in the ovaries, the oestrogen produced also causes a thickening of the lining of the uterus. Just before ovulation, oestrogen levels rise and this causes a rise in FSH and LH. LH triggers the egg to burst through the outer layers of the ovary and is then usually swept into the fallopian tubes.

Progesterone is mainly released by the corpus luteum and works with oestrogen to thicken the lining of the uterus ready for the implantation of a fertilised egg. It also helps to prepare the breasts for releasing milk. High levels of progesterone control the levels of GnRH, FSH and LH. We often test this at day 21 of a cycle to see if a female has ovulated.


What happens next depends on whether the egg is fertilised by sperm. If fertilisation occur, the corpus luteum continues to produce hormones. Another hormone called human chorionic gonadotrophin (hCG) is produced by the cells covering the embryo and stops the corpus luteum from breaking down. This is the hormone detected in pregnancy tests.

If the ovum is not fertilised, the corpus luteum can only live for about two weeks. As it begins to break down, it releases fewer of its hormones. As the levels of progesterone and oestrogen drop, they no longer control the levels of GnRH, FSH and LH. These hormones then increase and new eggs begin to develop – the start of a new cycle. In the uterus, the decrease in progesterone stimulates the release of chemicals that eventually cause the lining of the uterus to be shed. This is the blood flow experienced during menstruation.


Do I have a normal period, heavy period or menorrhagia?

About 1 in 3 women describe their periods as heavy. However, it is often difficult to know if your periods are normal or heavy compared with other women. Some women who feel they have heavy periods actually have an average blood loss. Some women who feel they have normal periods actually have a heavy blood loss. Most of the blood loss usually occurs in the first three days with either normal or heavy periods.

uterine cycle

Some medical definitions of blood loss during a period are:

A normal period is a blood loss between 30 and 40 ml (six to eight teaspoonful) per month. Bleeding can last up to eight days but bleeding for five days is average.

A heavy period is a blood loss of 80 ml or more. This is about half a teacupful or more. However, it is difficult to measure the amount of blood that you lose during a period. For practical purposes, a period is probably heavy if it causes one or more of the following: Flooding through to clothes or bedding, frequent changes of sanitary towels or tampons, double sanitary protection (tampons and towels or you pass large blood clots.

Menorrhagia means heavy periods that recur each month. Also, that the blood loss interferes with your quality of life. For example, if it stops you doing normal activities such as going out, working or shopping. Menorrhagia can occur alone or in combination with other symptoms.

What causes recurring heavy periods?

The cause is not known in most cases. This is called dysfunctional uterine bleeding (DUB) and is the cause of heavy periods in 4 to 6 out of 10 cases. In this condition, the womb (uterus) and ovaries are normal. It is not a hormonal problem. Ovulation is often normal and the periods are usually regular. It is more common if you have recently started your periods (teenagers) or if you are approaching menopause. At these times you may find your periods are irregular as well as heavy.

Other causes;

Uterine problems:
Fibroids: These are non-cancerous (benign) growths in the muscle of the womb. They often cause no problems, but sometimes cause symptoms such as heavy periods.

Endometriosis: this is when the lining of the womb grows in areas outside of the uterus, e.g. ovaries, bowel, bladder etc.

Infections, e.g. chlamydia

– Small fleshy lumps called polyps

Cancer of the lining of the uterus (endometrial cancer) – a very rare cause. Most cases of endometrial cancer develop in women aged in their 50s or 60s.

Hormonal problems:
– Periods can be irregular and sometimes heavy if you do not ovulate every month, e.g. this occurs in some women with polycystic ovary syndrome.

– Women with an underactive thyroid gland may have heavy +/- irregular periods.

– The intra-uterine contraceptive device; the copper coil (hormone free) can cause heavy periods in some women, the Mirena coil (contains progesterone hormone) can be associated with heavy bleeding in the initial phase after insertion, this usually settles down and the Mirena is actually often used to treat heavy periods.

– Warfarin or other medicines that interfere with clotting can cause heavy bleeding as they thin the blood.

– Some medications used to treat breast cancer (e.g. Tamoxifen) can cause heavy bleeding.

– If you stop taking the contraceptive pill it may appear to cause heavy periods. Some women become used to the light monthly bleeds that occur whilst on the pill. Normal periods return if you stop the pill and these may appear heavier but are usually normal (unless you were commenced on the pill to treat heavy periods and this recurs once treatment is stopped.)


Do I need tests if I have heavy periods?

A thorough history is key as this often reveals the cause of the heavy bleeding. More importantly however, appropriate history taking assesses for the red flags or sinister features associated with heavy bleeding;

– Bleed in between periods, or have irregular bleeding.

– Have bleeding or pain during, or just after, sex.

– Have pain apart from normal period pains.

– Have any change in your usual pattern of bleeding, particularly if you are over the age of 45.

– Have symptoms suggesting a hormonal problem or blood disorder.

It may also be worth keeping a diary for a few periods (before and after any treatment). Basically, you record the number of sanitary towels or tampons that you need each day and the number of days of bleeding. Also, note if you have any flooding or interruption of normal activities.

A doctor may want to do an internal (vaginal) examination to examine your neck of the womb (cervix) and also to assess the size and shape of your womb (uterus). However, an examination is not always necessary, especially in younger women who do not have any symptoms to suggest anything other than dysfunctional uterine bleeding. If the vaginal examination is normal (as it is in most cases) and you are under the age of 40, no further tests are usually needed. The diagnosis is usually dysfunctional uterine bleeding and treatment may be started if required. Further tests may be advised for some women, especially if there is concern that there may be a cause for the heavy periods other than dysfunctional uterine bleeding.

Blood tests:
– A blood test to check for anaemia is sometimes performed. If you bleed heavily each month then you may not take in enough iron in your diet, needed to replace the blood that you lose. (Iron is needed to make blood cells.) This can lead to anaemia which can cause tiredness and other symptoms. Up to 2 in 3 women with recurring heavy periods develop anaemia.

– Thyroid function

– Bleeding tests, if the history is suggestive of a bleeding disorder.

This is a painless and radiation free scan which is sometimes done to look at the ovaries and uterus. This involves use of a probe which scans through the abdominal wall and is also sometimes inserted into the vagina to gain better views of the pelvic structures.

Swab for infection:
These are sometimes performed if the history is suggestive of an ineffective cause.

Specialised tests:
A gynaecologist may decide to do a camera test to look into the womb and take some biopsies of the lining of the womb.


What are the treatment options for heavy periods?

Treatment aims to reduce the amount of blood loss.

– Not treating:
This is an option if your periods do not interfere too much with normal life. You may be reassured that there is no serious cause for your heavy periods and you may be able to live with them. A blood test may be advised every so often to check for anaemia.

– Levonogestrel intra-uterine system (LNG-IUS) e.g. Mirena.
The LNG-IUS is a coil that is inserted into the womb and slowly releases a small amount of a progestogen hormone called levonogestrel. The amount of hormone released each day is tiny but sufficient to work inside the uterus. In most women, it usually works very well with bleeding becoming either very light or stops altogether within 3-6 months of starting treatment. Period pain is usually reduced too. The LNG-IUS works mainly by making the lining of the uterus very thin. Each device lasts for five years, although it can be taken out at any time. It is particularly useful for women who require long-term contraception, as it is also a very reliable form of contraception.

– Tranexamic acid (TXA) tablets:
These tablets are an option if the LNG-IUS is not suitable or not wanted. TXA can reduce the heaviness of bleeding by almost half in most cases. You need to take a tablet 3-4 times a day, for 3-5 days during each period. It works by reducing the breakdown of blood clots in the uterus. In effect, it strengthens the blood clots in the lining of the uterus, which leads to less bleeding. If side-effects occur, they are usually minor but may include an upset stomach.

– Anti-inflammatory medications, e.g. Ibuprofen, Mefanamic acid:
These can reduce the bleeding by up to a quarter in most cases and also reduced period pain and you need to take the tablets for a few days during each period. They work by reducing the high level of prostaglandin in the lining of the uterus. This is a chemical which seems to contribute to heavy periods and period pain.

– The combined oral contraceptive pill (COCP):
This reduces bleeding by at least a third in most women and often helps with period pain too. It is a popular treatment with women who also want contraception but who do not want to use the LNG-IUS. If required, you can take this in addition to anti-inflammatory painkillers (described above), particularly if period pain is a problem.

– Long-acting reversible progesterone contraception:
The contraceptive injection and contraceptive implant can reduce bleeding in some patients, up to half of women with the contraceptive implant do not have periods after 1 year. However, these can also sometimes worsen heavy periods.

– Norethisterone:
This is a hormone (progestogen) medicine. It is not commonly used to treat heavy periods but is sometimes considered if other treatments have not worked, are unsuitable or are not wanted. Norethisterone is taken on days 5-26 of your menstrual cycle (day 1 is the first day of your period). Taking norethisterone in this way does not act as a contraceptive. It is not commonly used as a regular treatment because it is less effective than the other options.

– Surgical treatment:
Removing or destroying the lining of the uterus is an option. This is called endometrial ablation or resection. Only suitable for women who have completed their families as this prevents women from having children in the future (but cannot be relied upon as a form of contraception).

– Hysterectomy (remove the uterus); This is much less commonly done these days since the mirena coil and uterine ablation became available.

– If fibroids are the problem

– Surgical removal (myomectomy)

– Uterine artery embolization; essentially the blood supply to the fibroid is cut-off.

– MRI-guided ultrasound ablation of the fibroid, new therapy and still under review.


If you have heavy periods and would like to explore some treatment options, do contact us at Coyne Medical…we are happy to help!

Dr Vanessa Ni Churrain
Coyne Medical, GP