Heavy or prolonged periods can cause iron deficiency anemia. Anemia may impact periods, but this requires further research.

Iron deficiency anemia occurs if people do not have enough iron in the body for it to make healthy red blood cells. Heavier or longer periods can cause iron deficiency anemia.

This article examines the link between anemia and periods, treatment and prevention for irregular periods and anemia, and when to contact a doctor.

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There is little recent research on how anemia affects the menstrual cycle or periods.

Can anemia cause heavy periods?

Although heavy periods can lead to anemia, little current research suggests that anemia can cause heavy periods.

Older research from 1964 suggests that an iron deficiency may cause heavy periods.

Additionally, a 1989 case report suggests iron deficiency may cause abnormal bleeding. The report suggests anemia may be a cause of heavy periods in young teenagers.

Can anemia cause lighter periods or stop them altogether?

There is little research to suggest that iron deficiency anemia can cause lighter periods.

However, according to some research, 50% of females with iron-deficiency anemia also have amenorrhea, which is the absence of periods. A 2020 study on mice found that iron restriction decreased ovary function, follicle development, and fertility.

Iron deficiency may affect the menstrual cycle, but further human research is necessary to understand the link between iron levels, menstruation, and amenorrhea.

Doctors do not usually associate the cause of iron-deficiency anemia with amenorrhea, so they will have to rule out other causes of iron-deficiency anemia in those with both conditions.

Can anemia cause spotting between periods?

There is little research to suggest that anemia can cause spotting.

Spotting can occur with hormonal birth control, or it may be a sign of a health condition. People with concerns about spotting between periods can talk with a doctor.

Can anemia affect symptoms of premenstrual syndrome (PMS)?

According to a 2021 study, iron can affect premenstrual symptoms or premenstrual syndrome (PMS), as it has links to the production of serotonin, a neurotransmitter that helps with mood stability.

The study found that people at risk of iron overload, who may have higher iron stores in the body, may have some protection against some PMS symptoms. The researchers found no link between low iron levels and PMS symptoms.

A small 2020 study found that iron deficiency may lead to behavior disturbances and reduced cognitive performance. Some people may experience symptoms relating to these factors. Other research also suggests iron deficiency may influence emotional behavior.

Symptoms of anemia and PMS may overlap. Anemia and PMS may both cause symptoms such as:

Heavy periods can cause iron deficiency anemia. However, this is unusual. Anyone who thinks their anemia is due to heavy periods should talk with a doctor to find out the cause.

Signs that heavy periods might be causing anemia

A heavy period means needing to change a tampon or pad within 2 hours of use or if the discharge includes blood clots the size of a quarter or larger.

If heavy periods are causing anemia, people may experience:

Treating the cause of heavy periods and restoring iron levels may help treat anemia. In the same way, treating anemia may resolve anemia-related menstrual cycle changes.

If anemia is causing atypical periods, treatment may include:

If heavy periods are causing anemia, treating the underlying cause may help treat anemia in the long term. Possible causes of heavy periods include:

Treatment depends on the condition but may include medications such as tranexamic acid or hormonal therapy.

Ensuring people take in enough iron and treating heavy periods may help prevent abnormal periods and anemia.

Treating anemia may help prevent atypical periods due to low iron levels. Treating or preventing anemia may include:

  • eating a diet rich in iron and vitamin B12, such as leafy green vegetables, milk, meat, and eggs
  • taking iron and B12 supplements

If people have heavy periods, seeing a doctor to find out the underlying cause may help prevent prolonged blood loss, which, without treatment, can lead to anemia.

If people have heavy or irregular periods or any symptoms of anemia, they will need to contact a doctor.

A doctor can perform a blood test to check for anemia and can carry out other tests to determine what is causing heavy or irregular periods.

Anemia is more common in females. A 2023 review notes that heavy bleeding, iron deficiency, and anemia are common in females and can adversely affect quality of life. However, historically, bleeding conditions in females have been overlooked and under-resourced in terms of research.

Symptoms of anemia may also be more severe in females. A 2022 study compared symptoms of anemia in males and females and found that females had higher levels of fatigue and worse symptoms of anemia than males.

The difference in symptom severity may be due to genetic and biological differences, such as the structure of red blood cells, metabolism, biochemistry, and testosterone levels.

According to a 2024 commentary, risk factors for iron deficiency anemia include race and ethnicity. There are significant racial disparities in anemia screening during pregnancy, and Black females have an increased risk of life threatening complications due to anemia in childbirth compared to white females.

Stigma and a lack of knowledge about typical menstrual bleeding means people may not seek help for heavy periods, which can lead to anemia.

Can anemia affect the color of period blood?

Anemia may cause period blood to be pink in color.

How much does hemoglobin drop during a period?

A 2023 study of 31 females found hemoglobin (a protein in red blood cells) levels dropped from an average of 13.1 grams per deciliter (g/dL) to 11.9 g/dL after menstruation.

Periods that are heavy or longer than usual may lead to iron deficiency and anemia. Anemia may impact the menstrual cycle, although this requires further research.

If people have heavy or irregular periods or symptoms of anemia, they can contact a doctor. Increasing iron intake can help treat anemia.