What is a period diary?

Clinical Lead for Women's Health and Bupa GP
23 July 2025
Next review due July 2028

A period diary is a record of when your period starts and ends, how heavy your flow is, and any symptoms you experience each month. It’s sometimes known as a menstrual diary, or a period tracker . It can help you to monitor your cycle, understand your body better, and manage your symptoms. Here I’ll explain the benefits of keeping a period diary, and how to get started.

person texting on a mobile phone

What are the benefits of a period diary?

Here are some of the ways a period diary could help you.

1. Keep track of your cycle

Everyone’s menstrual cycle is a little different, but they usually last between 21-35 days. By tracking when your period begins and ends, you can get to know what’s normal for you and predict when your next period might start. This can help you to plan ahead and know:

  • when to take your sanitary products with you
  • when any symptoms might start
  • what phase of your cycle you’re in and how you might feel

2. Manage your symptoms

Making a note of your physical and emotional symptoms throughout the month can help you to find any patterns between your symptoms and your cycle. For example, if you regularly experience back pain, low mood, and headaches before your period each month, you might have premenstrual syndrome (PMS). Recognising these patterns means you can take steps to manage or reduce your symptoms each month.

3. Plan your schedule

The menstrual cycle is divided into four different stages.

It starts with your period, followed by what’s known as the follicular phase. After this, comes your fertile window, which is usually when you ovulate and are more likely to get pregnant. Finally, if you don’t get pregnant, you’ll enter the luteal phase. These are the days leading up to your period, when you might not feel your best.

You might find that your mood and energy change during each of these different phases. So, knowing where you are in your cycle can help you to plan your week. For example, if you often have pain and fatigue during your period, you might choose to go for a gentle walk.

You might want to save more intense exercise for the time of the month when you feel most energetic. Or if you notice your mood dips before your period, you might schedule in a night of self-care over a late night out with friends.

4. Know when you might ovulate

If you’re trying to get pregnant, it can be useful to know when you might ovulate (release an egg for fertilisation) each month. By recording your cycle, it can help you to predict when this might happen. But your most fertile days could vary, so it can help to use an ovulation test around this time too.

If you don’t want to get pregnant, it’s not enough to just avoid unprotected sex during ovulation. You can still get pregnant at other times in your cycle. So it’s important to use reliable methods of contraception, such as the contraceptive pill or condoms.

5. Recognise a potential health issue

It’s not always easy to know if your symptoms are part of a normal cycle, or if they’re a sign of an underlying condition like endometriosis or PCOS. Keeping a detailed record of which symptoms you get when, and how severe they are can help. You can share this information with your GP, who can use it to understand what might be causing your symptoms. They can guide you towards the right support and treatment.

How do I keep a period diary?

There are two main ways you can start a menstrual diary . You can choose to use a period tracking app, or a diary to track your symptoms. These both work in a similar way, but you might find the following tips helpful to get the most out of your period diary.

  • Note down your symptoms each day of the month as they occur, and remember that day one of your cycle is the first day of your period.
  • Be sure to include details of your energy levels, pain score, and any changes to your mood.
  • Record how heavy your flow is during your period.
  • Keep track of your cycle for at least three months so you can begin to identify patterns.
  • If you’re using a physical menstrual diary template , keep it somewhere handy, such as beside your bed, to remind you to use it.

Finally, if you’re worried about any changes in symptoms, increased pain or heavy bleeding, see your GP. They can help you to manage your symptoms.

Bupa’s period and symptom tracker (PDF, 1.4MB), can help you record and track your symptoms. Download our Menstrual diary PDF shown below.

Bupa's period and symptom tracker


If you have heavy, painful, or irregular periods, you’ll know just how disruptive they can be, both physically and mentally. With our Period Plan, you don’t have to face these problems alone.

Dr Samantha Wild
Clinical Lead for Women's Health and Bupa GP

 

Co-author

Michelle Harrison, Freelance Health Editor.

    • Hohmann-Marriott BE, Williams T and Girling JE. The role of menstrual apps in healthcare: provider and patient perspectives. New Zealand Medical Journal. 2023; 17(136): 42-53
    • Menstruation and menstruation disorders. Patient. patient.info/doctor, last updated April 2022
    • Patel U, Broad A et al. Experience of users of period tracking apps: which app, frequency of use, data input and output and attitudes. Reproductive Biomedicine Online 2024; 48(3): 103599. doi.org/10.1016/j.rbmo.2023.103599
    • Self-care for premenstrual dysphoric disorder (PMDD). Mind. mind.org.uk, published October 2024
    • Gudipally PR and Sharma GK. Premenstrual syndrome. National Library of Medicine [StatPearls Publishing]. ncbi.nlm.nih.gov, last updated July 2023
    • Wilcox AJ, Dunson D and Baird DD. The timing of the “fertile window” in the menstrual cycle: day specific estimates from a prospective study. BMJ, 2000; 321: 1259-1262 doi: 10.1136/bmj.321.7271.1259
    • Ovulation and fertility. Tommy’s. tommys.org.uk, last reviewed March 2024
    • Contraception – natural family planning. NICE Clinical Knowledge Summaries. cks.nice.org.uk, last revised June 2021
    • Pain and symptom diary. Endometriosis UK. endometriosis-uk.org, accessed July 2025
    • Polycystic ovary syndrome (PCOS). NHS inform. nhsinform.scot, last updated May 2023
    • Heavy periods. Women’s Health Concern. womens-health-concern.org, published November 2022

About our health information

At Bupa we produce a wealth of free health information for you and your family. This is because we believe that trustworthy information is essential in helping you make better decisions about your health and wellbeing.

Our information has been awarded the PIF TICK for trustworthy health information. It also follows the principles of the The Information Standard.

The Patient Information Forum tick

Learn more about our editorial team and principles >

Did you find our advice helpful?

We’d love to hear what you think. Our short survey takes just a few minutes to complete and helps us to keep improving our healthy lifestyle articles.

Content is loading