Tiredness and anaemia
Feeling tired is sometimes normal, but unexplained tiredness that has lasted for weeks should be checked. This page lists common causes and explains how anaemia is found and followed up.
Which tiredness should be taken seriously?
Come in if:
- You have been tired for a few weeks and do not know why
- Tiredness is affecting your daily life
- You have also lost weight or your mood has changed
- You have been told you gasp, snort or choke in your sleep
Common causes
Most of the time the cause lies in daily life: poor sleep and insomnia, an unhealthy diet and little exercise, stress, depression and grief. Hormonal changes, some infections and some medicines also cause tiredness.
When tiredness has no explanation and is not improving, these are looked at:
| Along with tiredness | Cause to check |
|---|---|
| Palpitations, breathlessness, pale skin | Iron deficiency anaemia |
| Great thirst, passing urine often especially at night, weight loss | Diabetes |
| Feeling cold, weight gain, constipation, dry skin | Underactive thyroid |
| Restlessness, anxiety, muscle weakness | Overactive thyroid |
| Waking up choking, loud snoring | Sleep apnoea |
This table is not for diagnosing yourself. It only shows why a doctor asks about things that seem unrelated to tiredness.
What is anaemia?
Anaemia means you have fewer red blood cells than normal, or too little haemoglobin in them. Haemoglobin carries oxygen around the body. The most common type is iron deficiency anaemia, often caused by blood loss or pregnancy. A lack of vitamin B12 or folate causes another type.
How is it checked?
A complete blood count (CBC) is the first step, and it needs no special preparation. Ferritin shows how much iron the body has stored. Low ferritin can be a sign of iron deficiency anaemia, and high ferritin does not only come from too much iron.
In iron deficiency, treating the number is not enough. The doctor needs to find out where the iron is being lost, for example through heavy periods or a stomach ulcer. If the reason is not clear, a stool test for hidden blood or a referral may be needed.
How is it treated?
Treatment depends on the cause. For iron deficiency anaemia, iron tablets are usually prescribed, and the blood test is repeated after a while. Iron tablets can cause constipation or diarrhoea, tummy pain and heartburn, and they darken the stools. If side effects bother you, do not stop; talk to your doctor.
A lack of B12 or folate should also be found early, because some of its nerve problems may not fully recover if treated late.
Frequently asked questions
Should I start iron tablets myself?
Not before a test and a cause. Too much iron also causes problems, and iron tablets must be kept away from children, because an overdose can be fatal for a child.
How long are iron tablets needed?
Your doctor sets the length, which is usually several months. A repeat test shows whether your iron is back to normal.
What if all my tests are normal?
Tiredness has causes that do not show in the blood, such as poor sleep, stress, depression and sleep apnoea. So your doctor also looks at your history and your sleep.
The first step, a calm conversation.
Go to the booking page or talk to support. Have your earlier results and your medicine list ready.