Let’s be real—periods can be hard to manage at times. The cramps, inconvenience, cravings, and hormonal changes may be overwhelming. When you add fatigue into the mix, the negative effects of every other symptom becomes intensified. But why do you get so fatigued during your period?

Fatigue—feeling overtired or having abnormally low energy—can interrupt your work, personal life, relationships, and well being.

In the field of functional medicine, we know that taking the time to understand the underlying source of the problem is the first step towards feeling better. Here are some of the causes of menstrual fatigue and how you can start feeling more like yourself during your period. 



Tiredness from dropping estrogen levels

In the weeks leading up to your period, your body prepares for a potential pregnancy with spikes in your estrogen levels. These hormones work in overdrive to create the perfect environment for a fertilized egg. Once your period arrives, your body realizes that you no longer need those high estrogen levels to sustain a pregnancy, causing them to drop off. 

This rollercoaster of hormones can contribute to the fatigue you feel during your period. Peeked estrogen levels give you energy and make your body feel high alert. When this switch flips, your energy levels will drop proportionately, leaving you feeling exhausted.

Stress—heightening every source of menstrual exhaustion

Your period can throw off your hormonal balance in more ways than one. The emotional inconsistencies, physical aches, and other menstrual symptoms you may experience may result in some serious stress. These stressors are taxing on both your mind and your body. 

When you feel tired, it can be challenging to perform well at work, school, or home. In this sense, fatigue is both caused by stress and creating it. This can create a toxic cycle of stress and fatigue that lasts for the duration of your period.

Low-quality sleep and your period

When you are experiencing cramps, discomfort, and other period pains, quality sleep may be hard to reach. Without adequate sleep, fatigue during your period is a given. 

On a normal day, you may be used to getting by with less than the recommended eight hours, but your period can take this sleeplessness to the next level. How do periods shift your lack of sleep into overdrive?

  1. Extra caffeine: You may be (knowingly or unknowingly) getting higher doses of caffeine during your period. It is natural to find yourself reaching for that extra cup of coffee to fight menstrual tiredness. Additionally, many period-specific medicines (like Midol Complete) include a dose of caffeine to help fight fatigue. If you aren’t careful, you will find that this fatigue fix actually makes your sleeplessness worse. 
  2. Aches and pains: How can you be expected to sleep well when you are cramping and aching? Period-related discomfort may prevent you from reaching a deep level of sleep. You may also find yourself getting up throughout the night for extra trips to the bathroom. You may find yourself waking up feeling like you didn’t sleep at all.
  3. Stress: As we mentioned before, periods cause extra stress. This can make it hard to fall or stay asleep—despite making you feel so tired. 

Your period is arguably when you need sleep the most. A variety of factors leave your body and mind desperately needing rest. When you are unable to achieve the sleep you need, your period can have you reaching a new level of exhaustion.

Estrogen dominance—fatigue from high levels of estrogen

While estrogen can give you energy, abnormally high levels of estrogen creates a hormonal imbalance. Your body’s estrogen will begin overpowering your body’s progesterone levels. Progesterone is responsible for regulating your period. It also plays a key role in offsetting the negative side effects that estrogen can create. One of these—as you may have guessed—is fatigue. When your estrogen levels are much higher than your progesterone levels, this condition is called estrogen dominance.

Pre-menopausal changes and challenges

As your body prepares for menopause, you will begin to notice differences in your period, body, and overall well being. This may include fatigue. 

Harvard Health Publishing reports that 40% of perimenopausal women have difficulty sleeping. Fatigue and other pre-menopausal challenges can seem overwhelming and inevitable. You are not alone in this transition. There are safe medical solutions that you can access for relief. Working closely with a doctor one-on-one can help you alleviate fatigue and other pre-menopausal symptoms. 

Underlying health issues—the dangerous side of menstrual fatigue

underlying health issues of menstrual fatigue

Unfortunately, period fatigue can be a sign of an underlying issue in your health. This is why menstrual fatigue and other severe symptoms require the attention of a doctor. While a doctor will help you arrive at a specific diagnosis, common culprits include hypothyroidism, iron-deficiency anemia, and anemia-inducing health issues.




Your thyroid is responsible for regulating your body’s metabolism. This system is key to converting nutrients into energy. When your thyroid is underactive, it will not produce the hormones necessary to give your body the energy it needs. These symptoms can be heightened during your period.

Iron-deficiency anemia

Red blood cells carry iron as a component of hemoglobin, which distributes oxygen throughout your body. When you have inadequate levels of iron, your body begins to slow down as your tissue and muscles stop getting the oxygen they need to function properly. This can lead you to develop iron-deficiency anemia. 

When you lose blood during your period, you also lose iron. This puts you at risk for developing this condition. The effects can be subtle or drastic, but its most common and prominent symptom is fatigue. 

When you have heavy, frequent periods, you are at a higher risk of developing iron-deficiency anemia. Several conditions can cause heavy periods and related fatigue, including:

Uterine fibroids

Uterine fibroids (also called leiomyomas) are small, often benign tumors that can grow in the uterine wall. Fibroids are relatively common, with 30% of women developing them before the age of 35 and nearly 80% of women developing them by the age of 50. Some women with fibroids are asymptomatic. However, for those who do experience symptoms, heavy bleeding can be a sign. This heavy loss of blood may cause you to develop iron deficiency anemia. 


Do you find yourself needing to change your pad or tampon multiple times each hour? Does your period often last for more than seven days? These heavy bleeding patterns are signs of menorrhagia. The CDC reports that this condition affects roughly 1 in every 5 American women. Menorrhagia can cause anemia and fatigue, and it may be the sign of a deeper feminine health issue. 


Endometriosis is a condition in which the type of tissue that forms the lining of the uterus is found outside of the uterus. During your period, these misplaced tissues grow and bleed like the lining of your uterus. This causes swelling, irritation, and even scarring. According to the American College of Obstetricians and Gynecologists, roughly 1 out of every 10 women has endometriosis. 

Heavy bleeding associated with each of these conditions can cause iron-deficiency anemia and the resulting fatigue. 

Tiredness before your period

While you might think that 7-days of menstrual fatigue sounds manageable, this tiredness can actually begin several days before your period does. For many women, PMS or PMDD causes fatigue and other negative symptoms in the days or weeks leading up to their period. 

  • PMS (premenstrual syndrome) is common, affecting more than 90% of menstruating women. Symptoms include bloating, headaches, moodiness, and fatigue.
  • PMDD (premenstrual dysphoric disorder) is a less common and more severe form of PMS, impacting up to 5% of menstruating women

When you feel tired before your period even begins, what chance do you stand against fatigue? This tiredness can carry through the end of your cycle. It may be especially unmanageable when you do not get the rest and recovery time you need before your period begins. 

What can I do to relieve menstrual fatigue?

When it comes to abnormal period symptoms, the key is to find and treat the underlying cause. That is why it is important to find a doctor who is willing to take the time to really talk with you and understand your symptoms.


A functional medicine practitioner can help. Rather than taking a surface-level approach to your feminine care, a functional medicine doctor will take the time to get to know you. By discussing your symptoms, examining your medical history, and completing lab tests, your doctor can bring you the clarity and relief you need. When dealing with intimate and serious issues with your period, the last thing you need is a traditional in-and-out doctor’s visit. 

Your period is not something you should have to suffer through each month. If you experience abnormal or intolerable levels of fatigue, pain, or other symptoms that might have been dismissed or undiagnosed by a traditional doctor, consider speaking with a functional medicine practitioner to find a better way forward. 

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