Fatigue screen at Leicester Hospital

What is a fatigue screen?

A fatigue screen is a set of blood tests used to look for common, treatable causes of ongoing tiredness, such as anaemia, thyroid problems or diabetes. It's usually offered alongside a discussion with a doctor about your symptoms and lifestyle.

Why might I need a fatigue screen?

You might be offered a fatigue screen, or choose to arrange one privately, if:

• you've felt unusually tired, drained or low in energy for 4 weeks or more
• your tiredness hasn't improved with rest or sleep
• you have other symptoms alongside your tiredness, such as unexplained weight change or breathlessness.

See your doctor promptly, rather than waiting, if new tiredness comes on suddenly, especially if you're older and previously well, or if it comes with unexplained weight loss, unusual bleeding, a fever, or swollen glands, as these can occasionally point to something needing quicker attention.

What are the benefits of a fatigue screen?

Many causes of ongoing tiredness, such as low iron or an underactive thyroid, are straightforward to treat once identified. A fatigue screen can rule these in or out, giving you and your doctor a clearer basis for next steps, whether that's treatment, a change in your lifestyle, or reassurance that nothing serious has been found.

Are there different types of fatigue screen?

• In-clinic blood test: a nurse or phlebotomist takes a blood sample from your arm, often alongside a consultation with a doctor about your symptoms and lifestyle.
• At-home finger-prick kit: you collect a small blood sample yourself at home using a lancet, then post it to a laboratory and view your results online.
• NHS assessment: your GP takes a history and examines you, then decides which blood tests to arrange based on your symptoms.

How do I prepare for a fatigue screen?

• take the test first thing in the morning if you can, before eating or taking any supplements
• if you take levothyroxine for your thyroid, take your test before that day's dose, unless your doctor has told you otherwise
• drink water beforehand, as being well hydrated makes it easier to give a blood sample
• check whether your specific test needs fasting, as this varies and will be detailed in your test information
• if you're anxious about the blood draw, you can bring a friend or family member to your appointment for support.

What happens during a fatigue screen?

1. You have a consultation, in person, by phone, or through a questionnaire, where you're asked about your symptoms, general health and lifestyle.
2. A blood sample is taken, either from a vein in your arm by a trained professional, or from a finger-prick sample you collect yourself.
3. If your sample needs to go to a laboratory, it's usually posted the same day, often with a tracked or pre-paid return service.
4. Your blood is tested for common causes of tiredness, such as thyroid function, blood sugar, and signs of anaemia or low iron.
5. If you see a doctor as part of the screen, they may also examine you and ask about any other symptoms.

What happens after a fatigue screen?

Results are usually available within a few days. Some in-clinic services report results within 24 hours, while postal tests depend on laboratory processing times.

If everything comes back within the normal range, this is reassuring, though it doesn't rule out every possible cause of tiredness, since factors like stress, sleep problems or lifestyle aren't picked up by blood tests. If your results show an underlying cause, such as low iron or a thyroid problem, your doctor can discuss treatment options with you.

If your tiredness has lasted 3 months or more, or continues despite normal results, your doctor may suggest further tests or a specialist referral.

What are the risks of a fatigue screen?

• Discomfort: a blood draw can cause brief discomfort, minor bruising, or light-headedness, particularly if you're anxious about needles.
• Low yield: most fatigue investigations do not lead to a clear diagnosis.
• False reassurance or anxiety: because most results are normal, testing doesn't always ease worry, and can sometimes lead to further tests being ordered without a clear benefit.
• Haemolysis: occasionally a sample can't be processed properly if the blood cells break down before reaching the laboratory, meaning you may need to repeat the test.