From the Guidelines
Low hemoglobin levels in females are primarily caused by iron deficiency, which can be attributed to heavy menstrual bleeding, pregnancy, poor diet, and gastrointestinal issues, as supported by the most recent study 1.
Causes of Low Hemoglobin in Females
The causes of low hemoglobin levels in females can be multifaceted, including:
- Heavy menstrual bleeding
- Pregnancy
- Poor diet
- Gastrointestinal issues
- Iron deficiency, which is the most common cause of anemia in females, as stated in 2 and further emphasized in 1
Importance of Iron Supplementation and Dietary Changes
To address low hemoglobin levels, iron supplementation and dietary changes are essential, as recommended in 1. This can include:
- Taking ferrous sulfate 325 mg once or twice daily between meals with vitamin C to enhance absorption
- Consuming lean red meat, beans, lentils, spinach, and fortified cereals to increase dietary iron
- Avoiding foods or fluids that impair iron absorption, such as tea and coffee, around meal times
Monitoring and Medical Evaluation
Regular follow-up blood tests are crucial to monitor improvement, and severe or persistent anemia requires medical evaluation to identify and treat underlying conditions, as highlighted in 3 and 4. If hemoglobin falls below 8 g/dL or symptoms like severe fatigue, dizziness, or shortness of breath occur, seek immediate medical attention as blood transfusion may be necessary.
Normal Hemoglobin Ranges
Women typically have lower hemoglobin levels than men due to menstrual blood loss, with normal ranges being 12.0-15.5 g/dL for women compared to 13.5-17.5 g/dL for men, as stated in 1 and 3. However, the definition of anemia may vary, and some studies suggest that women should be considered anemic if their hemoglobin level is <130 g/L, as proposed in 3.
From the Research
Causes of Low Hemoglobin Levels in Females
- Iron deficiency is a common cause of low hemoglobin levels in females, accounting for approximately one-half of anemia cases 5
- Blood loss is the most common cause of acute iron depletion and anemia worldwide, and reduced hemoglobin synthesis and anemia are the most common consequences of low plasma iron concentrations 6
- Menstruation is a significant source of blood loss in female athletes, contributing to low hemoglobin levels 7
- Heavy menstrual bleeding (HMB) and pregnancy/postpartum are also risk factors for iron deficiency and iron deficiency anemia in women 8
- Other causes of anemia include deficient erythropoiesis, excessive RBC destruction, and blood loss 9
Specific Causes
- Iron deficiency anemia (IDA) is defined as low Hb or hematocrit associated with microcytic and hypochromic erythrocytes and low RBC count due to iron deficiency 6
- Dilutional pseudoanemia, caused by exercise-induced fluid retention, is a common cause of low hemoglobin levels in athletes 7
- Chronic and inflammatory diseases, as well as increased needs during pregnancy, can also contribute to iron deficiency and anemia 6
Risk Factors
- Women of reproductive age are at higher risk of iron deficiency anemia due to menstrual blood loss and increased iron needs during pregnancy 6
- Female athletes are at risk of iron deficiency and anemia due to plasma expansion, increased perspiration, and foot strike hemolysis 7
- Pregnant and postpartum women are particularly vulnerable to iron deficiency and iron deficiency anemia 8