Period Fatigue: Why You Feel So Tired on Your Period

Why am I so tired on my period? The usual reasons are PMS, sleep that cramps or other period symptoms disturb, and low iron when your periods are heavy.

Tiredness that comes and goes with your cycle is common. Tiredness that stays all month, or comes with heavy bleeding, breathlessness or dizziness, needs a check with a doctor. This guide explains what period fatigue feels like, what causes it, what helps, and what to write down before your appointment. It is general information. Your own doctor decides what is right for you.

What period fatigue feels like

Period fatigue is more than a late night. Your body can feel heavy and slow, and small jobs can take more effort. You may want to nap more, or find it hard to focus.

Fatigue is among the physical symptoms of premenstrual syndrome (PMS). The emotional symptoms include insomnia, more naps, and poor concentration.

When in the cycle it shows up

For many people, the tired days come just before the period and in its first days. The usual PMS pattern is:

• Symptoms come in the 5 days before a period.
• They end within 4 days after the period starts.
• The pattern repeats for at least 3 cycles in a row.

So tiredness that lifts a few days into your period fits PMS. Tiredness that goes on for weeks after your period does not. Some other conditions can look like PMS. These include depression, anxiety, perimenopause, chronic fatigue syndrome, irritable bowel syndrome (IBS) and thyroid disease.

Common causes of feeling tired on your period

PMS

Fatigue is one of the symptoms of PMS. If you also have mood changes, bloating, sore breasts or headaches in the same days, PMS is a likely part of the picture. When the tiredness comes with body aches and a run-down feeling, people often call it period flu.

Poor sleep before and during your period

Sleep changes across the menstrual cycle. Poorer sleep in the days before a period and during the period is common in women who have PMS or painful cramps. In the second half of the cycle, sleep also changes in ways that may be linked to the hormone progesterone.

If cramps wake you at night, you lose sleep and feel it the next day. Our guide on how to describe period pain can help you explain night pain to your doctor.

Heavy bleeding and low iron

Heavy periods are a common cause of iron deficiency anaemia. Blood loss from heavy periods can also lead to iron-deficiency anemia.

Symptoms of iron deficiency anaemia include:

• Tiredness and lack of energy
• Shortness of breath
• Heartbeats you can feel (palpitations)
• Skin that is paler than usual
• Headaches

Feeling tired or short of breath a lot is also a sign that your periods may be heavy. So if you are tired every month and you bleed a lot, tell your doctor about both. Our guide to signs you are losing too much blood during your period shows how to tell.

When tiredness on your period is not typical

It can be normal to have heavy periods at some times, such as when periods first start, after pregnancy or near the menopause. But these signs can mean your bleeding is heavy:

• You soak through one or more pads or tampons every hour for several hours in a row.
• You need to change your pad or tampon every 1 to 2 hours, or use two products at the same time.
• You need to change pads or tampons during the night.
• Your period lasts more than 7 days.
• You pass clots about the size of a quarter (2.5 cm) or larger. Our guide to blood clots during your period explains what is normal.
• You bleed through to your clothes or bedding.
• You miss work or daily activities because of your period.

See a doctor if you have any of these, or if any of the following apply to you:

• You feel tired or short of breath a lot, you feel your heart beat hard, or your skin looks pale.
• The tiredness does not lift in the days after your period.
• You have severe pain during your periods.
• You bleed between periods or after sex.
• Your tiredness or other symptoms get in the way of your daily life.

Severe anemia can cause shortness of breath and raise the risk of heart problems. If you bleed very heavily and feel faint, dizzy or very short of breath, get urgent medical help. For milder lightheadedness, see dizziness during your period.

Your doctor may do blood tests. For iron deficiency anaemia, this is usually a full blood count.

What can help with period fatigue

Keep regular sleep times

Regular sleep habits may lessen fatigue and moodiness from PMS. This means you go to bed and wake up at the same times every day, weekends too.

Move your body most days

For many women, regular aerobic exercise lessens PMS symptoms and may reduce fatigue. Brisk walking, running, cycling and swimming all count. Aim for at least 30 minutes on most days of the week, all month, and not only on the days you have symptoms.

Adjust what you eat and drink

These diet changes can help with PMS:

• Eat more complex carbohydrates, such as whole grain bread, brown rice, beans and lentils.
• Eat less fat, salt and sugar.
• Avoid caffeine and alcohol.
• Eat six small meals a day, or add light snacks between three smaller meals.

If feeling sick makes it hard to eat on your period, our guide to nausea during your period has tips for keeping food and drinks down. If you have no appetite on your period, that guide explains why and how to eat enough.

Get your iron checked if your periods are heavy

Do not guess at iron. If you think you have iron deficiency anaemia, see a doctor for a blood test. If the test shows it, treatment is usually iron tablets for about 6 months, with iron-rich foods. The doctor will also look for the reason, such as heavy periods. If heavy periods affect your daily life, there are treatments that can help, so ask about the options.

Ask about treatment if symptoms stop your life

If lifestyle changes do not help enough, your ob-gyn may suggest medicine, based on how bad your symptoms are.

What to note before a doctor visit

"I'm always tired" is hard for a doctor to act on. A record over a few cycles gives a clearer picture. Write down and rate your symptoms every day for at least 2 to 3 months, and record the dates of your periods.

Each day, note:

• Cycle day. Day 1 is the first day of bleeding.
• Fatigue level from 0 to 10. Write 0 on good days too, so the pattern shows.
• Sleep. The hours you slept, and whether pain or bleeding woke you.
• Bleeding. Light, medium or heavy, how often you changed pads or tampons, any night changes, and any clots.
• Pain. How bad it was from 0 to 10, and where it was.
• Other signs. Breathlessness, dizziness, heartbeats you can feel, or low mood.
• Impact. Anything you missed, such as work, school or plans.

After 2 to 3 cycles, you can show your doctor which days the tiredness comes and how it lines up with bleeding and pain. Our guide to a pain diary for your doctor explains how to share a record like this.

Endolog is a pain and symptom diary app. You can log fatigue on the same day as pain and bleeding, so your doctor sees them side by side and you do not have to rely on memory in a short appointment.

Period fatigue and endometriosis

Extreme tiredness (fatigue) is a symptom of endometriosis, together with severe period pain and heavy periods. If your tiredness comes with period pain that stops your normal activities, raise endometriosis with your doctor. For sleep problems with endometriosis, read about endometriosis and insomnia.

About half of women with endometriosis had frequent fatigue in one study, compared with about 1 in 5 women without it. In that study, fatigue was linked with insomnia, depression, pain and stress at work. It was not linked with the stage of the disease. So tell your doctor about your sleep, your mood and your pain as well as the tiredness.

"I'm tired" can get the advice to sleep more. These details give your doctor more to work with:

• The impact. For example: "I had to nap for three hours before I could cook dinner."
• How it feels. For example, heavy arms and legs, or brain fog that makes it hard to focus at work.
• The timing. Whether it comes before your period, during it, or all month. Your fatigue scores from the diary above show this.

Frequently asked questions

Is it normal to be tired on your period?

Yes, it is common. Fatigue is a PMS symptom, and PMS symptoms usually end within 4 days after your period starts. Tiredness that lasts longer, or comes with heavy bleeding or breathlessness, is worth a check.

Can heavy periods make you tired?

Yes. Heavy periods are a common cause of iron deficiency anaemia, and tiredness is one of its main symptoms. A blood test can show it.

Why am I so tired before my period?

Fatigue is part of PMS, which comes in the 5 days before a period. Sleep quality is also often poorer before and during the period in people with PMS or painful cramps.

How do I stop feeling so tired on my period?

Keep regular sleep times, exercise most days, eat more complex carbohydrates, and cut down on caffeine and alcohol. If your periods are heavy, ask your doctor to check your iron.

This article is for general information. It does not replace care from a doctor. If you think you have an emergency, call 911 in the US, or 999 in the UK.