Iron deficiency: symptoms many doctors miss

Dr. Charalampos Romanos · April 14, 2026 · 5 min read

Iron deficiency is more common than many patients think — especially in women, vegetarians, and people with gastrointestinal disorders. But here's the problem: many doctors only look at fatigue and miss the other symptoms. As a GP in Zurich, I regularly see patients who have lived with iron deficiency for years without being diagnosed.

The classic symptoms — and what many miss

Most people immediately think of fatigue and pallor with iron deficiency. That's true, but it's only the tip of the iceberg. Hair loss is one of the symptoms I particularly often see overlooked. Patients go to dermatologists, receive expensive treatments — yet the problem was simple iron deficiency the whole time.

Restless legs and concentration problems

Another underestimated symptom is restless legs syndrome. Patients describe a tingling sensation in the legs at night, which disrupts sleep. And the cognitive effects are real: concentration problems, memory problems, even depressive symptoms can be caused by iron deficiency. The brain needs iron for myelin formation.

Why standard blood tests often aren't enough

Checking haemoglobin is necessary but not sufficient. I always also order ferritin, transferrin saturation, and TIBC. The ferritin value is particularly important — many patients already have low ferritin values before haemoglobin drops. This is the early warning sign that should be used before it becomes critical.

The most common causes in my practice

In women of reproductive age, heavy menstruation is the most common cause. In older patients, I look for occult bleeding in the gastrointestinal tract — this is sometimes a sign of something more serious. Vegetarians and vegans often struggle to absorb enough iron, as plant iron (non-heme iron) is poorly absorbed.

How I treat iron deficiency in my practice

Treatment begins with finding the cause — this is crucial. Then we start oral supplementation, ideally with vitamin C to improve absorption. In severe cases or when oral therapy doesn't work, we offer infusion therapy. An iron infusion works faster and is often better tolerated.

Prevention for at-risk patients

I recommend regular laboratory monitoring for patients with risk factors. This is part of my preventive medicine — recognise problems early before symptoms develop. Proper diet with iron-rich foods and optimising absorption is also important.