Period flu: why you feel unwell before and during your period

When you experience symptoms such as headache, nausea, stomach pain, and fever around your menstrual period, you may wonder if you are sick or even going insane.

Avatar illustration of a woman having period flu symptoms

Key takeaways:

  • Hormonal changes, chemical changes in the brain and genetic factors are some of the reasons why people may feel sick before and during their menstrual periods.
  • Some of the symptoms people experience as their body gets ready for their menstrual flow is called "period flu".
  • Symptoms of period flu include nausea and bloating, fatigue, and abdominal cramp. Experiencing these symptoms can make you feel unwell before and during your period.

When you are sick, your body tells you that. From mild unpleasant symptoms like headache, fatigue, and nausea to more intense symptoms like pain, shortness of breath, and confusion, your body signals that something is wrong either physically, physiologically, or anatomically.

But how do you make sense of the fact that the body gives you sickness signals when you are not really sick?

Welcome to the world of most people who menstruate.

Approximately 95% of people who have their period experience mild physical and physiological symptoms before or during their period. People commonly call this "period flu," but medically, it is considered part of a condition called premenstrual syndrome (PMS).

Bloating, fever, fatigue, and headaches are some of the symptoms of period flu. When you experience such symptoms, especially around the time you see your period, do not panic; it doesn't mean you are sick or dying. It's just your body signaling that it's about that time of the month again.

This article will discuss period flu, its signs and symptoms, and its causes more. It will also discuss how long period flu can last and what to do when you experience it.

What is period flu?

Period flu is a sign that you are about to get your period. It may happen because your hormone levels change during your menstrual cycle.

Period flu includes several symptoms that doctors classify under the term "premenstrual syndrome" because, in most cases, the symptoms appear just before the period and disappear with the menstrual flow.3

When you hear the term "period flu," it is easy to mistake it for the actual flu (influenza), but it's not. It has nothing to do with catching the flu and is not contagious. The term was coined because the symptoms, such as fatigue and body aches, are similar to influenza symptoms.

Period flu is the body's way of telling you that you will soon be getting your period. However, not everyone who menstruates gets these symptoms. Also, while some people experience mild symptoms, others experience more severe symptoms. However, most people get better with proper self-care, lifestyle, and dietary changes.

Is period flu normal?

Yes, period flu is considered normal. It is a common health issue among people who are of childbearing age. It is often accompanied by both emotional and physical symptoms. According to a 2017 study that looked at how common PMS is among college women who have their periods, about 92.3% have PMS.

Period flu is not life-threatening. However, it is important to pay attention to your body, as not all perceived symptoms are normal. If the symptoms last more than a few days or longer than your period, you should see your doctor.

Also, if the symptoms are severe, intense, debilitating, and affect your daily living, you should see a doctor because you may have premenstrual dysphoric disorder (PMDD).

Premenstrual dysphoric disorder is a more severe form of premenstrual disorder. It is characterized by more intense symptoms of PMS that can negatively impact daily living and quality of life.

Alongside physical symptoms, a person with PMDD may experience mental, emotional, and behavioral symptoms such as binge eating and feeling angry or depressed.

Signs and symptoms of period flu

Periodic flu can cause symptoms similar to influenza and give you the impression that you have the flu. Flu is an infection of the throat, nose, and lungs, while period flu is caused by your body's response to changes in hormones that happen during your period.

Period flu may cause signs and symptoms like:

  • Nausea and bloating
  • Crankiness and restlessness
  • Dizziness
  • Muscle aches
  • Fatigue
  • Waist pain
  • Stomach aches and cramps
  • Constipation and diarrhea
  • Fever or chills
  • Difficulty concentrating
  • Joint pain and backache
  • Headaches
  • Tender abdomen

Causes of period flu

Experts are not exactly sure why some people experience period flu, but it has been linked to menstrual cycle hormones like estrogen and progesterone. However, how these hormones trigger PMS symptoms is still unclear.

Scientists link period flu symptoms to the production of progesterone and chemical changes in the brain, such as fluctuations in serotonin levels.

PMS symptoms tend to appear with hormonal fluctuations during periods and usually go away during pregnancy and menopause. Also, fluctuations in serotonin, a neurotransmitter, can contribute to period flu, as serotonin plays an important role in regulating mood, sleep, and emotions.

An older theory proposed that prostaglandins contribute to the period flu symptoms people experience. Prostaglandins are compounds in the body with hormone-like properties. They are linked to muscle contraction, inflammation, pain, and uterine cramping.

Prostaglandin receptors are present in the uterus, and higher levels can cause PMS symptoms and more severe menstrual cramps.

Aside from hormonal fluctuations and changes in brain chemicals, or neurotransmitters, the American Family Physician suggests that genetic factors may also play a role in the period flu you experience.

How long does period flu last?

Period flu often appears some days before menstruation and usually goes away about 1–2 days after the period starts. Mood and emotion-related symptoms can last from a few days to two weeks, with the symptoms peaking about two days before menstruation.

Not everyone with a vagina will experience period flu. The symptoms will vary among those that experience it, as will the duration of the symptoms. It will help if you monitor your cycle and the symptoms you experience.

You can take notes and prepare for these symptoms before your actual period date. Taking notes will help you describe your symptoms to a doctor in case you need to see one regarding the symptoms.

What to do when you have period flu

Remember, experiencing period flu doesn't necessarily mean you are sick. Still, no one enjoys the unpleasant symptoms they feel as their body prepares for the monthly menstrual flow. Fortunately, some home remedies may help relieve period flu symptoms.

Things you can do when you have period flu include the following:

  • Drink enough water to stay hydrated.
  • Exercise more often.
  • Eat healthy meals.
  • Avoid eating sugary foods, alcohol, or caffeine. Some people notice that such foods worsen their symptoms.
  • Shower at least twice a day to help your body relax.
  • Try hot or cold compress; it may help relieve your symptoms, especially if you experience cramps.
  • Get enough sleep, as sleep deprivation has been linked to mood swings, anxiety, and crankiness.
  • Speak to your doctor about trying supplements. Some supplements may help ease some period-related symptoms.

When can I see a doctor

You should see a doctor if your period flu symptoms persist even after your period. You are also advised to seek medical attention if you are cramping more than usual or experiencing other related symptoms like irregular periods, extremely heavy flow, unexplained weight loss, or painful sex.

Period flu is just your body's response to some physiological changes and nothing to be worried, scared, or ashamed of.

A little change in lifestyle and home treatments can help ease the symptoms. However, don't hesitate to talk to your healthcare provider if the symptoms continue even after your period.

Do you experience symptoms that cause you discomfort before or during your period? Learn about foods that can help ease period symptoms.


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