Mood swings before periods: PMS or PMDD?

No one fully understands why, but the NHS says PMS may be linked to the changes in hormone levels during the menstrual cycle. Some women seem more affected by these changes than others.

Signs some women notice in the days or weeks before a period include:

• mood swings, feeling low or irritable
• feeling upset, anxious or emotional
• crying more easily, or angry outbursts
• wanting to be left alone
• trouble concentrating or sleeping
• tiredness, food cravings, bloating, sore breasts or headaches

So yes, it is common to feel sad before your period. It is also worth noticing when it starts, how strong it is, and whether it lifts once your period begins. That pattern is what helps a doctor.

PMS is the name for the physical and emotional symptoms many women get before their period, month after month. They can be uncomfortable, but most women can still manage daily life.

PMDD (premenstrual dysphoric disorder) is a severe form of PMS that affects a small number of women. The symptoms are similar but much more intense, and they can seriously disrupt work, relationships and everyday life. The NHS lists feeling very anxious, angry or depressed, and sometimes thoughts of suicide, along with headaches, joint and muscle pain, overeating and sleep problems.

It is not clear what causes PMDD. The NHS says it has been linked to being very sensitive to changes in hormones, or to differences in the genes you inherit. It is not a weakness and it is not "just moods".

Some other conditions can look like PMS or get worse before a period. The American College of Obstetricians and Gynecologists names depression, anxiety, perimenopause and thyroid disease among them.

The key difference is timing. With PMS, symptoms come before a period and ease once it starts. With depression or anxiety, they are often there all month and may get worse before a period. If your low or worried feelings never fully go away, read about depression in women and anxiety in women.

Changes in your periods themselves, such as irregular cycles, can also have other causes. If your cycle is irregular and you also notice acne, extra hair growth or weight changes, read about PCOD mood swings.

Keeping a simple diary is the most useful thing you can do before you see a doctor. The NHS suggests keeping a diary of your symptoms for at least two menstrual cycles; American gynaecologists suggest two to three months.

Each day, note:

• the date, and whether you are bleeding (mark the first day of your period)
• your mood: low, irritable, anxious, tearful, calm
• how strong it felt: mild, medium or strong
• sleep, energy and appetite
• body symptoms: cramps, headaches, bloating, sore breasts
• anything that made it better or worse

A notebook or the notes app on your phone is enough. After two cycles, look back. Do the hard days cluster before your period and ease once it starts? Or are they spread across the month? Either answer helps the doctor.

For many women, small changes to daily habits ease PMS symptoms. These come from NHS and ACOG advice.

• Move regularly, all month, not just on bad days. Brisk walking, cycling or swimming all count.
• Sleep at regular times. Going to bed and waking at the same time every day can ease moodiness and tiredness.
• Eat smaller, more frequent meals, with whole grains, dal and vegetables, and less salt, sugar and fat.
• Cut down on caffeine and alcohol, especially in the days before your period.
• Make room to unwind. Yoga, slow breathing or meditation can help with stress.
• Plan around your hardest days where you can. If your diary shows the last few days before your period are the toughest, avoid booking big things then.

If symptoms are strong or affect your daily life, a doctor can talk you through other options. Do not start supplements or medicines without asking a doctor first, especially if you take other medicines.

See a doctor if your symptoms are affecting your daily life, or if changes to your routine have not helped. Bring your two-cycle diary.

See a doctor soon if you notice very strong anger, anxiety or low mood before your period, if it is affecting your relationships or work, or if your mood is low all month, not just before your period.

If you are not sure whether what you feel is "normal", that is reason enough to talk to someone. A Nari health counsellor can listen, help you make sense of your diary, and book you with a Nari doctor. The doctor looks at your cycle and your mood together and decides on any tests. Counsellors never give medical advice; medical decisions come from a Nari doctor.

If you feel suicidal before your period, or at any time, get help now. Nari 1 is not an emergency service. If you are thinking of harming yourself, or you are in danger, call 112 now. For free mental health support at any hour, call Tele-MANAS on 14416 or 1-800-891-4416, a Government of India helpline.

• Your two-cycle diary, or as many days as you have.
• How long your cycle usually is, and whether it has changed.
• Which symptoms bother you most, and how they affect work or home.
• Whether low mood or worry is there all month or only before your period.
• Any past thyroid test, and any medicines, supplements or contraception you use.
• Any thoughts of harming yourself, even if they only come before your period.