Hematologist
CION Cancer Clinics
The workup for unexplained anaemia in older adults | CION Cancer Clinics
Doctors find the cause of unexplained anaemia in an older person in layers. They start with blood tests for iron, vitamin B12, folate, kidneys and thyroid, then check for hidden bleeding, and only then ask a haematologist to look at the bone marrow. This page walks you through each stage, what the results point towards, and how to decide with the doctor how far the tests should go. At CION Cancer Clinics, our haematologist cares for anaemia, bleeding, clotting and inherited blood disorders, with ArogyaSri, CGHS and cashless insurance accepted.
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Medically reviewed by Dr. Basudev PokhrelConsultant Haematologist · last reviewed September 2026, next review due September 2027
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On this page
- How do doctors find the cause of unexplained anaemia in an older person?
- What happens at each stage of the workup?
- What causes turn up once the tests are done?
- What does each first result point towards?
- What do families get wrong about the workup?
- How far should the tests go, and what can this page not tell you?
- Common questions about the anaemia workup
The short answer
How do doctors find the cause of unexplained anaemia in an older person?
They work in layers. First come simple blood tests for iron, vitamins, kidneys and thyroid, then tests for hidden bleeding, and only if those do not explain the low haemoglobin does a blood specialist look at the bone marrow.
What "unexplained" really means
Anaemia means a low haemoglobin, the oxygen-carrying part of the blood. It is called unexplained when the first round of tests has not shown a clear reason. That does not mean something serious is being hidden. In many older people the answer is a mix of small causes, such as slightly weak kidneys plus a little low iron, that no single test shows on its own.
Why the order matters
Starting with simple, cheap tests finds the common causes quickly and spares an older person needless procedures. Going straight to a marrow test, or skipping the check for bleeding, can miss the obvious answer or put a frail person through strain for little gain. A good workup is thorough and also sensible about the person in front of it.
Reference ranges differ between laboratories. A single result is always read alongside symptoms and repeat tests.The pathway
What happens at each stage of the workup?
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A careful history and examination
The doctor asks about tiredness, weight loss, appetite, black stools, night sweats and every medicine, including pain relievers, blood thinners and tonics. Old reports matter: a count that has fallen slowly tells a different story from one that dropped suddenly.
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The first blood tests
A full blood count with the size of the red cells, a blood film looked at under the microscope, iron studies, vitamin B12 and folate, kidney and liver tests, thyroid function and a reticulocyte count, which shows whether the marrow is trying to keep up.
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Looking for hidden bleeding
If iron is low, the gut is checked. This may mean a stool test, then a camera test of the stomach or bowel if the doctor and family agree it is worthwhile.
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Tests for the marrow and blood proteins
If nothing yet fits, tests such as protein electrophoresis, which looks for an abnormal protein made by myeloma cells, may be added. A haematologist, a blood specialist, then reviews the whole picture.
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A bone marrow test, if needed
A small sample is taken from the hip bone under local anaesthetic. It is offered only when the result would change the plan.
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What causes turn up once the tests are done?
Most older people end up in one of these groups, and some in more than one.
A shortage
Low iron, vitamin B12 or folate. Iron shortage in an older adult is treated as a sign of possible bleeding until shown otherwise.
Often linked to
- Stomach or bowel bleeding
- Poor diet or poor absorption
Kidneys and long-term illness
Weaker kidneys, arthritis, long infections and heart failure can all hold the count down. This is one of the most common findings in later life.
A marrow condition
Myelodysplastic syndrome, where the marrow makes faulty cells, or myeloma, a cancer of plasma cells. These are less common but are the reason a specialist review exists.
A change in other counts, such as white cells or platelets, makes these more likely.No single cause
For some elders, every test is close to normal and the anaemia stays mild and steady. Doctors may then watch with repeat counts rather than test further.
Reading the clues
What does each first result point towards?
What the report shows
What the doctor usually checks next
Small red cells and low ferritin, the iron store
A search for bleeding from the stomach or bowel
Large red cells
B12, folate, thyroid, liver, alcohol and medicines, then the marrow
Normal-sized cells with weak kidney tests
Whether kidney disease explains the whole picture
Low white cells or platelets as well
Early review by a haematologist
Raised blood protein or calcium, or bone pain
Tests for myeloma
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Commonly believed
What do families get wrong about the workup?
"If the first tests are normal, there is nothing wrong."
Normal first tests rule out some causes, not all of them. The haemoglobin is still low for a reason. The next layer of tests, or a careful watch with repeat counts, is how that reason is found.
"A bone marrow test is dangerous at this age."
It is done with local anaesthetic, takes a short time and is generally well managed by older people. It can be uncomfortable. The real question is whether the result would change the care, and that is worth asking directly.
"Let us just transfuse and skip the tests."
A transfusion lifts the count for a while but leaves the cause untouched. It also changes later blood results, making the cause harder to find. Some tests are best sent before any transfusion, if it is safe to wait.
"Being sent to a haematologist means it is blood cancer."
A referral means the common causes have not fully explained the result. Many people seen by a haematologist turn out to have a benign cause.
Did you know
Old blood reports are one of the most useful things you can bring. A count that has been falling slowly for years and one that dropped recently send the workup down very different paths, so gather every report you can find, even the crumpled ones.
Being straight with you
How far should the tests go, and what can this page not tell you?
Not every older person needs every test. The aim is to find a cause that can be treated, or to rule out one that would change the care. For a person who is very frail, or who would not want treatment for a marrow condition, a camera test or marrow test may add strain without changing anything.
Questions worth asking the doctor
Ask what each test is looking for, and what would happen if it came back abnormal. Ask whether the result would change treatment. Ask whether watching with repeat counts is a reasonable choice. These questions help the family and the doctor agree on a plan that fits your parent's health and wishes.
What this page cannot tell you
It cannot tell you which tests your parent needs, or what their results mean. A haematologist reads each result alongside symptoms, other illnesses and earlier reports. At CION, the haematology team reviews unexplained anaemia, discusses complex cases at a tumour board and arranges any specialised tests with qualified centres.
Questions we are asked
Common questions about the anaemia workup
What blood tests are done for unexplained anaemia in the elderly?
Usually a full blood count with red cell size, a blood film, iron studies including ferritin, vitamin B12 and folate, kidney and liver tests, thyroid tests and a reticulocyte count. If these do not explain it, doctors may add protein tests for myeloma. The exact list depends on the person's symptoms and earlier results.
Does my father need a bone marrow test?
Not always. It is usually considered when the simpler tests have not found a cause, when other counts are abnormal, or when the count keeps falling. It is offered when the result would change the plan. If he is very frail, it is fair to ask whether it would.
Why do they want a camera test of the stomach and bowel?
Low iron in an older adult often comes from slow, hidden bleeding in the gut, from ulcers, inflamed patches or growths. A camera test is the most direct way to find it. The doctor weighs how useful it would be against how well your parent would cope with the preparation and the procedure.
Should my mother stop her blood thinner while tests are done?
No, not on her own. Stopping a blood thinner can raise the risk of a stroke or clot. If a test needs it paused, the doctor who prescribed it will say exactly how and when. Tell every doctor involved which blood thinner she takes before any procedure is booked.
What if all the tests come back normal?
Some older adults have mild anaemia with no single cause found. If the count is steady and there are no worrying symptoms, doctors often watch it with repeat blood tests. A new fall, weight loss, or changes in other counts would be a reason to look again.
Can the tests be done before the transfusion?
Often, yes. Samples for iron, B12, folate and a blood film are best taken before transfused blood mixes in and changes the results. But if the person is unwell with a very low count, the transfusion comes first. The treating team decides which is safer.
Does CION do the bone marrow test itself?
CION's haematology team evaluates the case, reviews the reports and presents complex cases at a tumour board. Where a specialised test is needed, the team coordinates it with qualified centres. Ask which centre will do the test and when the result will be discussed with you.
Is unexplained anaemia in old age a sign of cancer?
Sometimes, but not usually. Kidney disease, long-term illness and vitamin or iron shortage are far more common. Bowel growths, myeloma and marrow disorders are among the causes the workup is designed to find or rule out. That is why the tests are worth doing when they would change care.
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.
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Sources
- NHS — Iron deficiency anaemia
- NHS — Vitamin B12 or folate deficiency anaemia
- National Heart, Lung, and Blood Institute — Anemia
- American Society of Hematology — Blood disorders: patient education
- Cancer Research UK — Myelodysplastic syndromes (MDS)
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
Anaemia in Older Adults: Never Just AgeingWhy a low count in later life needs a reasonWhen Not to Investigate Further in Old AgeWeighing more tests against frailtyMGUS and Low Counts in Older AdultsWhen the protein test shows somethingBlood Disorders in Older AdultsThe guide to blood problems in later life
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Tests done but still no answer?
Share the reports with us, old and new. CION's haematology team will review them and tell you what is worth checking next. One helpline serves every CION centre.