Hematologist
CION Cancer Clinics
What causes iron deficiency in women | CION Cancer Clinics
Heavy periods are the most common cause of low iron in women, often alongside pregnancy, breastfeeding and a diet low in iron. After menopause, periods no longer explain it, so doctors look for bleeding from the stomach or bowel. This page explains the usual causes by stage of life, how a doctor finds yours, and why the cause matters more than the tablet. At CION Cancer Clinics, our haematologist cares for anaemia, bleeding, clotting and inherited blood disorders, with ArogyaSri, CGHS and cashless insurance accepted.
BP
Medically reviewed by Dr. Basudev PokhrelConsultant Haematologist · last reviewed September 2026, next review due September 2027
17+specialists on panel
15,000+patients treated
35+centres across Telangana & AP
4.8★ / 800+Google rating
The short answer
What usually causes low iron in women?
In women who still have periods, the most common cause is blood lost through heavy periods, often alongside pregnancy and a diet low in iron. After menopause, periods no longer explain it, so bleeding from the gut has to be looked for.
Why women run short more often than men
Every period takes some iron out of the body. Pregnancy and breastfeeding pass iron to the baby. Many women in Telangana and Andhra Pradesh also eat mostly vegetarian meals and drink tea with food, which makes iron harder to absorb. Put together, the store empties slowly over years, often without anyone noticing.
Why the cause matters more than the number
Iron tablets can refill the store. But if the reason is still there, the store empties again within months. Worse, tablets can hide a slow bleed that needed finding. So a good doctor asks why your iron is low before deciding how to treat it.
Often there is more than one cause
A woman with heavy periods may also have had two pregnancies close together and a diet short of iron. Each cause on its own might be manageable. Together they tip the balance, and each one needs its own answer.
!
Signs that should not wait
If you are bleeding very heavily and feel faint, breathless at rest or your heart is racing, go to the nearest emergency department or call 108. Black, tarry stools, blood in your stools, or any bleeding after your periods have stopped for good need a doctor within days, not months. Do not treat these with iron tablets first.
Not sure whether this applies to you?
Ask an oncologistThe usual suspects
Which causes do doctors look for?
Most women have one or two of these. Your doctor works through them in roughly this order.
Heavy periods
The leading cause before menopause. Many women do not realise their periods are heavy, because they have always been that way.
Often behind it
- Fibroids or polyps in the womb
- Hormone changes, including PCOS
- A copper IUD
Pregnancy and breastfeeding
The baby and placenta draw heavily on your store. Pregnancies close together leave little time to rebuild it.
Diet and absorption
Iron from plants is absorbed less well than iron from meat or fish. Tea, coffee and calcium taken with meals reduce it further.
The gut
Coeliac disease, long use of acid-lowering tablets, stomach infection or past stomach surgery all cut absorption.
Bleeding causes
- Piles or a stomach ulcer
- Regular painkillers such as ibuprofen
- Growths in the bowel, more likely with age
Less common causes
Hookworm, frequent blood donation, blood lost in urine, or a bleeding disorder such as von Willebrand disease, which can make periods heavy from the very first one.
By age and stage
Does the likely cause change with age?
Stage of life
What is usually checked first
Teenage girls
Heavy early periods, diet, worms, and a bleeding disorder if periods were heavy from the start
Women in their twenties to forties
Heavy periods, fibroids, recent pregnancies and diet
Pregnant or breastfeeding
Higher need for iron, handled with your obstetrician
After menopause
The stomach and bowel, usually with a scope test, plus coeliac disease
Leave a number, we will call you
One field. No form to fill in, and no charge for the call.
The workup
How will the doctor find your cause?
-
Questions about your periods
Expect detailed questions. Heavy bleeding usually means periods that last longer than a week, soak through pads so often that you change them every hour or two, or bring large clots. Any of these is a strong clue, even if you have always thought your periods were normal.
-
Diet, pregnancies and medicines
How many pregnancies, how close together, what you eat, how much tea you drink, and whether you take painkillers or acid-lowering tablets.
-
Blood tests
Haemoglobin, ferritin, transferrin saturation and often a coeliac test and thyroid check. Reference ranges differ between laboratories, so the results are read alongside your symptoms and repeat tests.
-
A pelvic ultrasound
If periods are heavy, a scan looks for fibroids, polyps or a thickened womb lining, and a gynaecologist takes it from there.
-
Gut tests when needed
After menopause, or when periods do not explain the shortage, a stool test and a camera test of the stomach or bowel are often advised.
Commonly believed
What do families often get wrong?
"Every woman is a little weak. It is normal."
Low iron is common, but it is not normal. Tiredness, hair fall, breathlessness on stairs and poor concentration often lift once the cause is treated. It is worth checking, not putting up with.
"Heavy periods run in our family, so there is nothing to find."
A family pattern can point to fibroids or an inherited bleeding disorder. Both can be looked for and treated. Heavy periods are a reason to see a doctor, not a reason to accept low iron.
"She has stopped her periods, so her low iron must be diet."
After menopause, diet alone is rarely the whole answer. Doctors look for bleeding from the stomach or bowel first, because some of those causes are easier to treat when found early.
"Eating more spinach and jaggery will fix it."
Food helps keep a store full. It rarely refills an empty one, especially while the cause is still active. Diet works alongside your doctor's treatment, not in place of it.
Being straight with you
What can this page not tell you?
This page lists the usual causes. It cannot tell you which one is yours. Only a history, an examination and the right tests can do that, and sometimes the first answer turns out to be only part of the story.
Who should not simply start iron
Iron tablets are not for everyone with tiredness. Women with thalassaemia trait, liver disease or a normal iron result can be harmed by extra iron. Women past menopause should have the cause looked for before treatment. Your doctor decides whether you need iron, and in what form.
When a haematologist helps
Most women are looked after by a family doctor or gynaecologist. A haematologist, a blood specialist, is useful when iron keeps dropping despite treatment, when tablets do not raise haemoglobin, when a bleeding disorder is suspected, or when other blood counts are abnormal too.
Bring every blood report you have, and a note of how many days your periods last and how often you change pads.Questions we are asked
Common questions about low iron in women
What is the most common cause of low iron in women?
Before menopause, it is heavy periods, often combined with pregnancy and a diet low in iron. After menopause, bleeding from the stomach or bowel becomes the main thing to rule out. Many women have more than one cause, so your doctor will usually check each of them rather than stopping at the first.
How do I know if my periods are too heavy?
Clues include soaking through a pad every hour or two, needing to change at night, passing large clots, bleeding through to clothes, or periods that stop you going out. If you are not sure, keep a simple diary of days and pads for two or three cycles and take it to your doctor.
Can low iron come back after I finish tablets?
Yes, if the cause is still there. Heavy periods, a new pregnancy or a slow bleed will empty the store again. That is why doctors look for the reason, and why repeat blood tests after treatment matter. If low iron keeps returning, ask for the cause to be looked at again.
Is a vegetarian diet enough to cause low iron?
It can contribute, especially with tea at meals, but on its own it is rarely the full explanation in an adult woman. Dals, green leafy vegetables, millets and jaggery all help, and vitamin C from lemon or amla improves absorption. Your doctor will still ask about periods and the gut.
Could low iron be a sign of cancer?
In most women it is not. Periods and pregnancy explain the large majority. After menopause, a bowel or stomach growth is one of the causes doctors check for, which is why a scope test may be advised. Checking early is sensible. It is not a sign that cancer is likely.
Do worms really cause low iron?
Hookworm feeds on blood in the gut and can cause steady iron loss, particularly where people walk barefoot on soil. Deworming is part of India's national programme for this reason. Your doctor may ask about it or check a stool sample, especially in teenage girls and women from rural areas.
Who should I see first, a gynaecologist or a physician?
If your periods are heavy, a gynaecologist is a good start. If periods are normal or have stopped, a physician or gastroenterologist is usually the first stop. A haematologist is useful when tests do not add up, iron treatment is not working, or a bleeding disorder is suspected.
Can CION's haematology team review my reports?
Yes. Share your blood reports and any scan results, including older ones. The haematology team will look for patterns, tell you which tests are missing, and suggest which specialist should see you next. Call the helpline to arrange a review.
Your Haematologist
Meet CION's haematologist. One specialist for your blood report and your plan.
Dr. Basudev Pokhrel reviews blood counts, transfusion needs and blood disorders, and works with the CION tumour board on blood cancers.
Want a specific doctor for your case? Mention them when booking.
Book Free ConsultationBook an appointment with our specialist
Share your name and number — we'll call you back within 30 minutes to schedule your consultation.
Sources
- NHS — Heavy periods
- NHS — Iron deficiency
- NICE — Clinical Knowledge Summaries: iron deficiency
- National Heart, Lung, and Blood Institute — Iron deficiency
- National Health Mission — National Health Mission
This page is general information, not a prescription. Do not change or stop any treatment based on what you read here. If anything is worrying you, contact your own treating team — or call our helpline and we will help you reach the right specialist.
Keep reading
Related pages
Heavy Periods and Chronic Iron LossThe most common cause, in detailIron Deficiency in Men and Postmenopausal Women: The GI WorkupWhat the gut tests after menopause involveIron Deficiency in PregnancyWhen the need for iron risesRecurrent Iron Deficiency: Finding the Real CauseWhen low iron returns after treatment
Talk to us
Low iron that keeps coming back?
Share your blood reports with us. CION's haematology team will look for the pattern and tell you which test or specialist comes next. One helpline serves every CION centre.