Anaemia, iron and hair loss: what the link is

Anaemia means having fewer healthy red blood cells or less haemoglobin than normal, so the blood carries less oxygen around the body. The World Health Organization describes it as a widespread public health problem, particularly affecting young children, menstruating women and pregnant women ¹. The most common cause is not having enough iron, and hair loss is one of the possible symptoms ².

Iron and hair: what is the link?

Hair follicles are among the most actively dividing cells in the body, and they need a steady supply of nutrients. When iron is low, the body prioritises essential organs, and hair growth may slow or more hairs may enter the resting phase and shed.

The evidence is strongest for iron deficiency anaemia, where a blood test shows both low iron stores and low haemoglobin. Researchers have also studied whether low iron stores without anaemia (often measured as a low ferritin level) contribute to hair loss. The results have been mixed: some studies found lower iron stores in women with hair loss, others did not ^{3 4}. Many dermatologists still check iron levels in people with shedding, because low iron is common and easy to treat.

Signs of iron deficiency

The NHS lists these common symptoms of iron deficiency anaemia ²:

• Tiredness and lack of energy
• Shortness of breath
• Noticeable heartbeats (palpitations)
• Pale skin

Other symptoms can include headaches, a sore tongue, changes in taste, itchy skin, ringing in the ears and hair loss. Some people have no obvious symptoms at all.

Who is more at risk?

• Women with heavy periods. This is one of the most common causes in women of reproductive age ²
• Pregnancy and after giving birth. Iron needs rise during pregnancy. See postpartum hair loss
• Diets low in iron. Including some vegetarian and vegan diets that are not well planned, and restrictive weight-loss diets. See hair loss after weight loss
• Blood loss from the gut. For example from stomach ulcers or, especially in men and older adults, conditions of the bowel that need investigating ²
• Frequent blood donation or conditions that affect iron absorption

What hair loss from low iron looks like

Hair loss linked to low iron is usually diffuse, meaning hair thins or sheds across the whole scalp rather than in patches. It can look like telogen effluvium, and it can also make existing pattern thinning look worse ⁵. Round bald patches are not typical and suggest a different cause. See alopecia areata.

Getting tested

A GP can arrange a blood test, usually a full blood count and often a ferritin level, which shows how much iron is stored in the body ². A doctor may also look for the cause of the low iron. This matters: in men and in women after menopause, iron deficiency can be a sign of bleeding in the gut that needs investigating.

Treatment

If you have iron deficiency anaemia, a doctor will usually prescribe iron tablets and recheck your blood after some weeks ². Iron tablets can cause side effects such as constipation, diarrhoea, stomach pain or black stools. Treating the cause, such as heavy periods, is just as important.

Once iron levels recover, hair shedding caused by low iron often settles. Because of the hair cycle, improvement can take several months to show ⁶.

Do not take iron "just in case"

It can be tempting to take an iron supplement because your hair is falling. This is not a good idea without a blood test:

• Too much iron can cause side effects and, over time, can be harmful ⁷
• Iron supplements are a common cause of accidental poisoning in young children, so keep them out of reach
• Some people have conditions that cause the body to store too much iron
• Taking iron can hide the signs of an underlying cause that needs treatment

Reviews of vitamins and minerals for hair conclude that supplements are most useful when a deficiency is confirmed ⁴. See vitamin deficiencies and hair loss.

Iron in your diet

Good sources of iron include red meat, beans and lentils, nuts, dried fruit, fortified breakfast cereals and dark green leafy vegetables ⁷. In Malaysian meals, that can include lean beef or mutton, chicken liver, ikan bilis, tempeh, tofu, dhal, kangkung and bayam. Iron from plant foods is absorbed better when eaten with foods rich in vitamin C, such as guava or citrus fruit, and tea or coffee with meals can reduce absorption.

When to see a doctor

See a GP if you have hair loss with tiredness, breathlessness, palpitations or heavy periods, or if you have been told you are anaemic before. Seek medical advice promptly if you notice blood in your stools, black stools or unexplained weight loss.

The bottom line

Low iron is a common, treatable cause of hair shedding, especially in women. Get a blood test rather than guessing, treat the cause, and expect hair to take months to recover. For other medical causes, see when hair loss can be a sign of illness.

Frequently asked questions

Can low iron cause hair loss?

Yes. Hair loss is a recognised symptom of iron deficiency anaemia. The link with low iron stores without anaemia is less certain, but doctors often check it ^{2 3}.

Will my hair grow back after iron treatment?

Shedding caused by low iron often settles once levels recover, but it usually takes several months to see a difference ⁶.

Should I take iron supplements for hair loss?

Only if a blood test shows you need them. Too much iron can be harmful, and low iron may have a cause that needs treatment ^{7 4}.

What is ferritin?

Ferritin is a protein that stores iron. A blood test for ferritin shows how much iron your body has stored ².

Educational content. Not medical advice.