Pernicious anaemia

Overview

Pernicious anaemia is a condition where your body cannot absorb enough vitamin B12 from food. Vitamin B12 is needed to make healthy red blood cells and keep your nervous system working properly.

Pernicious anaemia is not very common. It affects about 0.1% of people in the general population, but it becomes more common with age.

It most often affects people over 60, but it can occur at any age. People with certain autoimmune diseases or a family history of pernicious anaemia are at higher risk.

Symptoms

Common symptoms

• Feeling very tired and weak
• Shortness of breath, especially with activity
• Pale or yellowish skin
• A fast or irregular heartbeat
• Tingling or numbness in hands and feet
• Trouble with balance and walking
• Memory problems or confusion
• A sore, red tongue or mouth ulcers

Symptoms in children

• Slow growth and development
• Weakness or constant tiredness
• Pale skin
• Irritability or behaviour changes
• Poor appetite or weight loss

Symptoms in older adults

• Memory loss, confusion, or dementia-like symptoms
• Trouble walking or frequent falls
• Numbness or tingling that gets worse over time
• Fatigue and weakness that affect daily activities

Causes

Main causes

• An autoimmune reaction where the body attacks cells in the stomach that make a protein called intrinsic factor. Intrinsic factor is needed to absorb vitamin B12.
• Lack of intrinsic factor prevents the body from taking in vitamin B12 from food, leading to deficiency over time.

Risk factors

• Having other autoimmune conditions like type 1 diabetes, thyroid disease, or vitiligo
• Family history of pernicious anaemia
• Being over 60 years old
• Having had stomach surgery or removal of part of the stomach

When to see a doctor

See a doctor urgently if:

• If you have shortness of breath, chest pain, or a very fast heartbeat
• If you have new numbness, weakness, or trouble walking
• If you feel very confused or have sudden memory problems

Book a routine appointment if:

• If you have been feeling tired for weeks without a clear reason
• If you have tingling in your hands or feet
• If you have a sore tongue or mouth ulcers that don't heal
• If you notice your skin becoming pale or yellowish

Diagnosis

Your doctor will ask about your symptoms, do a physical exam, and order blood tests to check your vitamin B12 level and other markers. They may also look for antibodies related to pernicious anaemia.

Tests that may be done

• Blood test for vitamin B12 level
• Blood test for intrinsic factor antibodies or parietal cell antibodies
• Complete blood count (CBC) to check for anaemia
• Sometimes a test of stomach acid or a biopsy of the stomach lining

What to expect at your appointment

The tests are simple blood draws. If your results suggest pernicious anaemia, your doctor will usually start treatment right away, often with B12 injections. You may be referred to a haematologist (blood specialist).

Treatment

Treatment for pernicious anaemia focuses on replacing the missing vitamin B12. This is usually done with injections given by a healthcare provider. Treatment is lifelong for most people.

Self-care at home

• Keep a regular schedule for your B12 injections or any prescribed supplements.
• Eat a balanced diet rich in folate and other vitamins, but do not rely on food alone to treat B12 deficiency.
• Stay active and manage stress to support overall health.

Medical treatments

The main treatment is vitamin B12 injections. These are given by a nurse or doctor, often every other day at first, then every few months for maintenance. Some people may also benefit from high-dose oral vitamin B12 tablets, but this depends on the cause and severity. Your doctor will decide the best plan for you.

When is surgery considered?

Surgery is not used to treat pernicious anaemia itself. If you have complications like stomach cancer (rare), that would be treated separately.

Living with this condition

Most people with pernicious anaemia manage well with regular B12 injections and occasional blood tests. You can live a full, active life. Keep a record of your treatment and symptoms to share with your doctor.

Lifestyle tips

• Plan ahead for your injection appointments – set reminders.
• Wear a medical alert bracelet or card in case of emergency, so healthcare workers know you have pernicious anaemia.
• Avoid smoking and limit alcohol, as they can affect vitamin absorption.

Diet and exercise

Eat a balanced diet with plenty of folate-rich foods (leafy greens, beans, oranges) and foods naturally high in B12 (meat, fish, eggs, dairy). However, diet alone cannot fix a lack of intrinsic factor. Exercise can help with energy and mood – start slowly if you have been very tired.

Mental health and emotional wellbeing

Dealing with a long-term condition can sometimes lead to feelings of anxiety or depression. The fatigue and neurological symptoms can also affect mood. It's important to talk to your doctor if you feel down, as counselling or support groups can help.

Prevention

Pernicious anaemia is an autoimmune condition, so you cannot prevent it directly. However, early diagnosis and treatment can prevent complications.

Vaccines

No vaccine prevents pernicious anaemia. But staying up to date with recommended vaccines is important for overall health, especially if you have an autoimmune condition.

Screening programmes

Screening is not routinely done for pernicious anaemia. If you have a family history or an autoimmune condition, your doctor may check your B12 levels as part of regular blood tests.

Complications

If left untreated

• Permanent nerve damage leading to numbness, weakness, and trouble walking
• Heart problems such as heart failure or arrhythmias (irregular heartbeat)
• Increased risk of stomach cancer (rare but serious)
• Mental health problems like depression and cognitive decline
• Problems with pregnancy if untreated during pregnancy

Long-term outlook

With regular treatment, the outlook for pernicious anaemia is very good. Most people can expect to live a normal lifespan and have few or no symptoms. Early treatment helps prevent long-term complications.

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