Patients with heavy periods often describe their symptoms in detail to their family physician for years before the connection to iron is finally made. Fatigue. Brain fog. Hair shedding. Sometimes restless legs. Their bloodwork is "normal" because the haemoglobin is in range. Ferritin was never checked. Eventually the picture is recognised — usually after the patient pushes for it — and the obvious link snaps into place.
How much is "heavy"?
Clinically, menorrhagia is defined as more than 80 mL of blood loss per cycle. In practice, very few patients measure their losses. More useful markers in the office:
- Soaking through a pad or tampon hourly for several hours in a row
- Bleeding through to clothing or bedding
- Passing clots larger than a quarter
- Periods lasting longer than 7 days
- Symptoms severe enough to disrupt work, sleep, or daily activities
If a patient describes any of the above, it is reasonable to consider their cycles heavy enough to drive iron loss.
The blood-loss math
Each millilitre of whole blood contains roughly 0.5 mg of iron. An 80 mL cycle therefore loses 40 mg of iron, or about 480 mg per year. For comparison, daily non-menstrual iron losses (skin, GI tract) are 1 to 2 mg per day — about 500 mg per year. A heavy-period patient is essentially doubling her annual iron expenditure, and very few diets can keep up.
The deficit is gradual. Iron stores deplete first; haemoglobin holds steady for months to years before finally dropping. By the time the CBC is abnormal, the patient has often had symptoms for a long time.
Why a normal CBC isn't reassuring
Haemoglobin is the last thing to fall. The body protects red cell production at the expense of iron stores. A normal CBC therefore tells you nothing about whether a patient is iron-deficient. The test that matters is ferritin.
In our practice, ferritin below about 30 ng/mL in a non-inflamed patient is enough evidence to consider iron deficiency in someone with consistent symptoms. Many internists treat at ferritins up to 50 ng/mL when the clinical picture fits — the literature increasingly supports this threshold over older cutoffs.
Two parallel tracks
When heavy bleeding has caused iron deficiency, the management has two components — neither replaces the other:
- Replenish iron. Oral iron is first-line for many patients. When oral is poorly tolerated or insufficient for ongoing losses, IV iron is an effective alternative.
- Investigate the bleeding. Gynaecology referral for evaluation of fibroids, polyps, hormonal causes, bleeding disorders, or other contributors. Treatment options range from tranexamic acid and hormonal therapy to procedural management.
When IV iron is the right answer
- Oral iron is not tolerated (common — nausea, constipation, taste effects)
- Oral iron is failing to raise ferritin despite consistent use
- Losses are ongoing while gynae work-up is in progress
- The patient is symptomatic and needs faster repletion than oral can deliver
- There is planned surgery and time pressure to correct deficiency beforehand
Modern IV iron formulations (ferric derisomaltose / Monoferric, ferric carboxymaltose / Ferinject, iron sucrose / Venofer) are typically given as a single or small number of infusions and replete stores rapidly.
What our clinic adds
The Iron Infusion Clinic at MED1 specifically handles the iron side of this picture: full panel, structured assessment, infusion on site when indicated, and direct communication with your family doctor and gynaecologist. Most referred patients are seen within the same week.