17790 Hemoglobin Test

Overview

A hemoglobin test is a simple blood test. It measures how much hemoglobin is in your blood. Hemoglobin is the protein inside your red blood cells that carries oxygen from your lungs to the rest of your body, and brings carbon dioxide back. Hemoglobin is measured in grams per litre (g/L) or grams per decilitre (g/dL), depending on where you live. Doctors often order this test as part of a full blood count (FBC) — a group of tests that look at all the different cells in your blood. The number '17790' is just a lab code used by some health services to identify this particular test. It is not a disease, and having the test does not mean anything is wrong. It is a routine way to check how well your blood is carrying oxygen.

Very common. Millions of hemoglobin tests are done every year. It is one of the first tests a doctor orders when someone feels unusually tired, looks pale, is pregnant, is having surgery, or is living with a long-term health condition.

Anyone can have this test. It is especially common in people with heavy periods, pregnant women, young children and teenagers going through growth spurts, people with digestive problems, people with long-term kidney disease or inflammation, vegetarians and vegans, older adults, and anyone with a family history of inherited blood conditions.

Symptoms

Common symptoms

• Feeling tired or lacking energy even after rest
• Skin, lips, gums or nail beds looking paler than usual
• Getting out of breath more easily than you used to, especially walking up stairs
• Feeling dizzy or lightheaded
• Headaches or trouble concentrating
• Cold hands and feet
• A fast or pounding heartbeat
• Brittle nails or a sore tongue
• For high hemoglobin: headaches, blurred vision, flushed or reddish skin, and itching after a hot shower

Symptoms in children

• Looking pale, especially around the lips and eyelids
• Being more tired or grumpy than usual, or tiring quickly during play
• Poor appetite or slow weight gain
• Slower growth than expected
• Getting breathless or dizzy during sport
• Frequent infections or trouble concentrating at school

Symptoms in older adults

• Ongoing tiredness or weakness that is put down to 'just getting older'
• Breathlessness during light activity such as dressing or walking to the shops
• Chest pain or palpitations with mild exertion
• Dizziness, unsteadiness or falls
• Confusion or memory changes that come on gradually
• Pale skin, or a swollen, smooth tongue

Causes

Main causes

• Low hemoglobin (anemia): not enough iron in the diet or poor iron absorption
• Blood loss, such as heavy periods, bleeding ulcers, piles, or surgery
• Low vitamin B12 or folate, which the body needs to make red blood cells
• Long-term kidney disease, because the kidneys make a hormone that tells the body to produce red blood cells
• Long-term inflammation or infection, which can slow red blood cell production
• Inherited blood conditions such as thalassemia or sickle cell disease
• Bone marrow problems, where the body does not make enough blood cells
• Pregnancy, because the body makes more blood plasma and the hemoglobin level can look lower
• High hemoglobin: dehydration (not enough fluid in the body)
• High hemoglobin: smoking, living at high altitude, or sleep apnea (breathing pauses during sleep)
• High hemoglobin: heart or lung conditions that lower the oxygen in your blood
• High hemoglobin: rarely, a bone marrow condition that makes too many red blood cells

Risk factors

• Heavy or long periods
• Pregnancy or recently giving birth
• A diet low in iron, B12 or folate, including some vegetarian and vegan diets if not well planned
• Digestive conditions such as coeliac disease, Crohn's disease or having had stomach surgery
• Taking blood-thinning medicines
• Long-term conditions such as kidney disease, diabetes, cancer or autoimmune disease
• A family history of inherited blood disorders
• Being an older adult, or a child or teenager during rapid growth
• Frequent blood donation or endurance sport
• Smoking or living at high altitude

When to see a doctor

See a doctor urgently if:

• You have chest pain, fainting, or severe breathlessness — call your local emergency number right away
• You notice blood in your stool, black stools, or blood in your urine
• You feel your heart racing or pounding and you feel unwell
• A hemoglobin result comes back very low or very high and you have not yet spoken to a doctor
• A child looks pale, is feeding poorly, or is unusually sleepy

Book a routine appointment if:

• You have felt unusually tired for more than a few weeks and it is not improving with rest
• You are more breathless than expected for your level of activity
• You have heavy periods
• You follow a restricted diet and want to check your iron, B12 or folate
• You have a long-term condition and your doctor has suggested a blood check
• You have a family history of anemia or an inherited blood condition

Diagnosis

The hemoglobin test itself is how the level is measured. A healthcare professional takes a small sample of blood — usually from a vein in your inner arm using a fine needle, or from a tiny prick on your fingertip or heel (for babies). The sample goes to a laboratory, where a machine counts your blood cells and measures the hemoglobin. The result is compared with a reference range, which is the typical range for someone of your age and sex. Your doctor will then think about why your level is outside that range, using your symptoms, your medical history, your diet, and any other tests.

Tests that may be done

• Full blood count (FBC) — shows hemoglobin plus the size and number of your red cells and other blood cells
• Blood film — a look at your blood cells under a microscope
• Iron studies, including ferritin — shows how much iron your body has stored
• Vitamin B12 and folate levels
• Reticulocyte count — shows whether your bone marrow is making new red cells
• Kidney and liver function tests
• Tests for inflammation
• Hemoglobin electrophoresis — checks for inherited conditions such as thalassemia or sickle cell disease
• A stool test, or referral for a camera test of the gut, if bleeding is suspected
• A repeat hemoglobin test, to see whether the level is changing

What to expect at your appointment

The test takes only a few minutes. You may feel a quick sting when the needle goes in, and there may be a small bruise afterwards. You usually do not need to fast, though if other tests are being done at the same time you may be asked to. Results normally come back within a few hours to a few days. Your doctor or nurse will explain the number, what the reference range is, and whether anything else needs checking. Ask for a copy of your results if you would like to keep track.

Treatment

There is no single treatment for an abnormal hemoglobin level, because the treatment depends entirely on the cause. The hemoglobin test is a clue, not the whole story. Once your doctor finds out why your level is low or high, they can suggest the right steps. Often this is something simple, such as eating more iron-rich foods, taking a supplement your doctor recommends, or treating an infection. Sometimes it means checking for bleeding or another underlying condition.

Self-care at home

• Eat iron-rich foods such as lean meat, beans, lentils, dark green leafy vegetables, nuts and fortified cereals
• Pair plant sources of iron with vitamin C (for example, fruit or peppers) to help your body absorb it
• Keep tea, coffee and calcium supplements away from iron-rich meals, as they can block absorption
• Drink enough water through the day, especially if your hemoglobin is high
• Rest when you feel tired, and build activity up gently rather than pushing through
• Keep a simple note of your symptoms and how they change, to share with your doctor
• Do not start iron or vitamin supplements on your own — too much iron can be harmful, so ask your doctor or pharmacist first
• Attend follow-up blood tests so your level can be tracked

Medical treatments

Treatment is aimed at the cause. If you are low in iron, vitamin B12 or folate, your doctor may prescribe a supplement and suggest dietary changes, then recheck your blood after a few weeks or months. If bleeding is found — for example from the gut or from heavy periods — that bleeding is treated. Some people with long-term kidney disease are given a hormone treatment that helps the body make red blood cells. If anemia is severe or you lose a lot of blood suddenly, you may be given blood through a drip in hospital. If hemoglobin is high, the focus is on treating the cause, such as dehydration, sleep apnea, smoking or a heart or lung condition, and in rare cases a specialist may recommend removing some blood or other treatments. Your care team will explain the options and check how you are getting on.

When is surgery considered?

Surgery is not used to treat a hemoglobin level itself. Occasionally, an operation may be needed to stop bleeding that is causing anemia, such as repairing an ulcer or removing a growth in the bowel. Very rarely, specialist surgery may be considered for certain bone marrow or spleen conditions. Your doctor will discuss this with you only if it applies to your situation.

Living with this condition

Most people with a mildly low or high hemoglobin level carry on with normal life while the cause is being looked into. If you feel tired, plan your day with short rests, and spread heavier tasks across the week rather than doing them all at once. Keep your appointments for repeat blood tests — they are how you and your doctor see whether things are improving. Carry your results with you if you move between services, and tell any health professional you see that you are being monitored.

Lifestyle tips

• Eat a balanced diet with enough iron, B12 and folate, and plenty of fruit and vegetables
• Stay active with gentle exercise such as walking or swimming, building up slowly
• If you smoke, ask your doctor or pharmacist for help to stop — smoking raises hemoglobin and harms blood vessels
• Limit alcohol, which can affect how your body uses vitamins
• Get enough sleep, and ask about a sleep apnea check if you snore heavily or feel exhausted after a full night
• Keep up with any treatment for long-term conditions such as kidney disease or diabetes

Diet and exercise

Food is a big part of keeping your blood healthy. Iron comes in two forms: from meat (which the body absorbs easily) and from plants (which the body absorbs less well, but pairing with vitamin C helps). Good plant sources include lentils, chickpeas, beans, tofu, spinach, kale, nuts and fortified breakfast cereals. B12 is found mainly in animal foods, so people eating a vegan diet usually need a supplement — ask your pharmacist or doctor which one suits you. Exercise is safe and helpful for most people with mild anemia, but start gently and stop if you feel dizzy or very breathless. If your level is very low, check with your doctor before starting a new exercise plan.

Mental health and emotional wellbeing

Ongoing tiredness can wear you down. It is common to feel frustrated, worried, low in mood, or to find it hard to concentrate at work or with family. This is a real part of the experience and nothing to be ashamed of. Tell your doctor how you are feeling — tiredness that affects your mood is worth mentioning, and it often improves once the cause is treated. If you ever feel hopeless or have thoughts of harming yourself, please reach out to a crisis line or emergency service in your area straight away. You do not have to cope alone.

Prevention

The test itself is not something you prevent — but many of the problems it picks up can be prevented or found early. Eating a balanced diet, treating heavy periods, avoiding smoking, staying well hydrated and keeping long-term conditions under control all help keep your hemoglobin in a healthy range. You cannot prevent inherited blood conditions, but knowing about them early means you can be monitored and supported.

Vaccines

No vaccine prevents anemia or abnormal hemoglobin. Keeping up with your routine vaccinations as advised by your health service is still good for your general health, and some vaccines are especially important if you have a long-term condition or have had your spleen removed.

Screening programmes

Hemoglobin is checked in many routine situations: pregnancy care, the newborn blood spot test in some countries, routine NHS health checks for adults, pre-operative assessments before surgery, and monitoring for people with long-term conditions. If you have a family history of an inherited blood condition, ask your doctor whether you should be offered a screening test. People with heavy periods or a restricted diet can simply ask for a blood check.

Complications

If left untreated

• Anemia that slowly gets worse, causing increasing tiredness and breathlessness
• Strain on the heart, which can lead to an irregular heartbeat or, over time, heart failure
• Problems with growth, learning and behaviour in children
• Extra risks during pregnancy for both mother and baby
• A weaker immune system and slower recovery from illness
• With very high hemoglobin, thicker blood that can raise the risk of clots
• Undiagnosed bleeding from the gut or another source being missed
• Lower quality of life, poorer sleep and difficulty at work or school

Long-term outlook

The outlook is usually very good. Most causes of an abnormal hemoglobin level are found quickly and are treatable — low iron is by far the most common, and it usually improves within a few weeks to a few months with the right advice. Inherited conditions and long-term illnesses can be managed well with regular monitoring and support. The important thing is to have the test explained properly and to keep your follow-up appointments, so any problem is caught early when it is easiest to treat.

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