Period health: What you need to know

Understanding period health and menstrual cycles can be complex. It's not always clear what's 'right' or 'wrong', or if indeed there is a definitive answer. You might on some months find yourself Googling ‘Is my period normal?’, or ‘how long is a typical menstrual cycle?’ Add to that the many myths which surround this women’s health topic and it’s no wonder you’re left confused.

So, we’re taking a look at all things periods. From the length of menstrual cycles, when to seek some medical guidance, and why what you’ve read might actually be a myth.

What is a period?

A period is the phase of the menstrual cycle during which a woman experiences vaginal bleeding for typically around 5 days. While the average cycle is considered to be 28 days, periods can occur earlier or later than this timeframe. According to the NHS, menstrual cycles can range from 21 to 35 days.¹

Clots are also a normal part of a period. If you see them on your towel or tampon, then it’s nothing to worry about. They are your body’s way of stopping too much blood being lost from the blood vessels in the lining of your womb.

If, however, they’re frequently over 2.5cm then it’s worth getting it checked out with your GP.

Irregular periods

Even though there is guidance on a typical menstrual cycle length, there are many women who go longer than 35 days without a period or have one that’s less than 21 days apart. These are known as irregular periods.

It’s thought that between 14% to 25% of women have irregular menstrual cycles, meaning:

• the cycles are shorter or longer than normal,
• they are heavier or lighter than normal.²

If your period lasts more than 7 days, is heavy, occurs more than once a month or you’re bleeding after sex, then it’s advised to see your GP to get checked out.³

Causes of irregular periods

Life stages and lifestyle triggers can be the cause of irregular periods, these include:

• puberty, when you start your periods,
• the start of menopause (usually between the ages of 45 and 55),
• pregnancy – a missed period is often an early sign of pregnancy,
• hormonal contraception like the progestogen-only pill, contraceptive injection and intrauterine system (IUS),
• losing or gaining a lot of weight,
• stress and anxiety,
• exercising too much.⁴

Is there a “normal” period?

Symptoms, duration, and heaviness can be different for each woman, and even different again every month on an individual level. What's normal for you may not be the same for someone else, and that's ok. It's important to understand and become familiar with your own menstrual cycles and what is normal for you.

Typically, a woman will lose around 20 to 90ml (1 to 5 tablespoons) of blood during a period, with the bleeding being the heaviest in the first few days.¹

If you lose more than 80ml of blood, so you’re needing to change your towel or tampon every 1 to 2 hours, or clots are bigger than 2.5cm, and it’s lasting more than 7 days, then this is considered heavy, and you should see your GP.

Having heavy periods doesn’t necessarily mean there’s a problem, but it does need to be investigated. It may turn out that heavy bleeding may just be normal for you, and in many cases, no underlying cause is found.⁵

What can affect periods?

As well as lifestyle factors such as stress, smoking, weight loss or gain and menopause, there are medical conditions that can affect periods and the symptoms you might get on a monthly basis.

Polycystic ovary syndrome (PCOS)

This is a condition that affects how the ovaries work and has 3 main features:

• irregular periods – which means your ovaries do not regularly release eggs (ovulation)
• excess androgen – high levels of "male" hormones in your body, which may cause physical signs such as excess facial or body hair
• polycystic ovaries – your ovaries become enlarged and contain many fluid-filled sacs (follicles) that surround the eggs (but despite the name, you do not actually have cysts if you have PCOS)⁶

Symptoms of PCOS can also include weight gain, thinning hair, oily skin or acne and difficulty getting pregnant. Although there is no cure for the condition, speak with your GP who can help with managing the symptoms. Changes to lifestyle, such as maintaining a healthy weight and eating a balanced diet, can help.

>Read more on the causes and the treatments for PCOS

Endometriosis

Endometriosis is a long-term condition where cells, similar to the lining of the womb, start to grow in other areas of the body, such as the ovaries and fallopian tubes. It can cause very heavy and painful periods, where daily activities become hard to carry out.

It’s different from period pain as during a period the walls of the womb contract which compresses the blood vessels lining your womb. This temporarily cuts off the blood supply, and oxygen supply, to your womb. Without oxygen, the tissues in your womb release chemicals that trigger pain.⁷

In endometriosis the pain is caused by tissue that has grown outside the uterus. It is during a period that these endometrial cells break down and bleed, however, this internal bleeding has no way of leaving the body which results in inflammation, intense pain and a build-up of scar tissue.

>Read more about what endometriosis is

Pelvic inflammatory disease

This is an infection of the ovaries, fallopian tubes and womb and can cause painful and heavy periods, as well as bleeding between periods and after sex.⁸

Period symptoms

Symptoms can occur before and during a period. The symptoms that occur before the period are collectively known as premenstrual syndrome (PMS) and can begin up to two weeks before your period is due. Common symptoms include:

• breast tenderness,
• bloating or tummy pain,
• headaches,
• tiredness,
• feeling sick (nausea),
• diarrhoea,
• lower back pain,
• breakouts of spots (acne),
• feeling upset, anxious or depressed,
• food cravings,⁹

>Read more on what PMS is

During your period it’s common to experience period cramping and pain in your lower tummy. It usually lasts between one to three days and is worse in the first 24-36 hours after bleeding starts.

It’s different for every woman but for some the pain can interfere with normal life and stop us going to work, to school, or out with friends. If your period pain is so severe it’s affecting your daily life, it’s important to speak to your doctor - there are treatments that can help.¹⁰

Period myths

1) Myth: You can’t skip a period?

Fact: you can delay or stop a period with hormonal treatment. If you have an upcoming holiday, or a special event like a wedding, you can consult your GP about a progestogen hormone tablet called norethisterone. Taken three days before your period is due, it can then be continued until you want to have a period.¹¹

For women taking the combined oral contraceptive pill then start the next pack without the usual seven-day break.

Please speak to a GP first to explore your options.

2) Myth: You can’t swim during your period

Fact: you can indeed swim when on your period. Finding the right period product for you, for example tampons, menstrual cups or period swimwear, can mean you can carry on swimming as normal.

3) Myth: there are some foods that can delay your periods or help with cramps

Fact: no food can delay a period. Equally, avoiding or eating more of certain foods won’t help any period cramps. There are numerous myths around the world on what a woman should or shouldn’t eat, from lemons to meat – none of which are based on scientific evidence.

4) Myth: you cannot get pregnant while on your period

Fact: if you have unprotected sex when on your period then you can get pregnant. The chances might be low as it can depend on the length of your menstrual cycle and when you are most fertile.

The shorter your cycle, the more likely it is that your fertile window will fall during your period, meaning there is a chance that you could get pregnant during that time.¹²

It’s worth remembering that no two periods are the same and what’s normal for you might not be the same for someone else. If you have any concerns about your periods or symptoms, then speak with your GP.

Further reading:

• Top tips for managing endometriosis
• What is PMS 
• Understanding Polycystic ovary syndrome (PCOS)

References

1. Periods - NHS
2. What are menstrual irregularities? – National Institute of Health
3. Irregular Periods: What Is the Cause and When Should You Seek Medical Help? – Women’s Health
4. Causes of irregular periods - NHS
5. How to tell if your bleeding is heavy – Healthily
6. PCOS - NHS
7. Period Pain – NI Direct
8. What can affect my ‘normal’ period? - Healthily
9. What are the signs that you’re getting your period? - Healthily
10. What is severe period pain? – Wellbeing of Women
11. Delaying a period - Patient
12. Can you get pregnant on your period? - Flo