What are the common causes and initial management steps for low hemoglobin in a young female?

Common Causes of Low Hemoglobin in Young Females

Iron deficiency anemia is the most common cause of low hemoglobin in young females, affecting 15-35% of female athletes and requiring thorough investigation to identify underlying causes. 1

Primary Causes

1. Menstrual Blood Loss

• Heavy menstrual bleeding is a leading cause of iron deficiency in young women 1
• Regular monthly blood loss creates ongoing iron demands that may exceed dietary intake

2. Nutritional Deficiencies

• Inadequate dietary iron intake, particularly in:
  • Vegetarians and vegans (highest risk) 1
  • Those with limited red meat consumption
  • Diets high in foods that impair iron absorption (tea, coffee, high fiber)

3. Gastrointestinal Causes

• Occult blood loss from:
  • Peptic ulcer disease
  • Inflammatory bowel disease
  • Celiac disease (found in 3-5% of iron deficiency anemia cases) 2
  • Gastritis with or without H. pylori infection

4. Increased Physiological Demands

• Endurance training and high-impact sports (running) 1
• Pregnancy
• Adolescent growth spurts

Diagnostic Approach

Initial Laboratory Evaluation

1. Complete blood count with:

   • Hemoglobin level
   • Mean corpuscular volume (MCV)
   • Red cell distribution width (RDW)
   • Reticulocyte count

2. Iron studies:

   • Serum ferritin (most sensitive test for iron stores) 2
   • Serum iron
   • Total iron binding capacity (TIBC)
   • Transferrin saturation

Diagnostic Pitfalls

• Ferritin is an acute-phase reactant and may be falsely elevated during inflammation 1
• Microcytosis may be absent in combined deficiencies
• Assuming a single cause when multiple factors may contribute 2

Initial Management Steps

1. Iron Supplementation

• Oral iron therapy: 60-120 mg elemental iron daily 1
• Administer between meals for better absorption
• Continue treatment for 2-3 months after hemoglobin normalizes 1
• Consider vitamin C co-administration to enhance absorption 1

2. Dietary Counseling

• Increase consumption of iron-rich foods:
  • Heme iron sources (meat, seafood) have better bioavailability than plant sources 1
  • Avoid tea and coffee around meals as they impair iron absorption 1

3. Addressing Underlying Causes

• Evaluate and treat heavy menstrual bleeding if present
• Screen for celiac disease in appropriate cases 2
• Consider gastrointestinal evaluation if:
  • No obvious cause identified
  • Poor response to iron supplementation after 4 weeks 1

4. Follow-up Monitoring

• Repeat hemoglobin after 4 weeks of treatment
  • Expect increase of ≥1 g/dL to confirm diagnosis and treatment response 1
• If no improvement despite compliance, further evaluation needed

Special Considerations

Differential Diagnosis

• Thalassemia traits (particularly in women of African, Mediterranean, or Southeast Asian ancestry) 1
• Anemia of chronic disease
• Other nutritional deficiencies (B12, folate)

When to Refer

• Severe anemia (Hb <8 g/dL)
• Poor response to oral iron therapy
• Suspected significant underlying pathology

Iron deficiency anemia in young females requires a systematic approach to identify and address the underlying cause while replenishing iron stores to prevent long-term consequences on health and quality of life.