If you are always tired, a small set of targeted blood tests can rule out common medical causes such as anaemia, low iron, an underactive thyroid, diabetes and problems with the kidneys or liver. These tests are useful, but most persistent tiredness is not explained by a blood result, so the conversation with a doctor matters as much as the tests themselves.
Investigating tiredness is one of the most common reasons people come to our private GP service. This guide explains which tests are worth doing, which are not, and when tiredness needs a doctor sooner.
Why am I always tired?
Tiredness is extremely common, and it usually has more than one cause. Before any blood test, a doctor will want to understand your sleep, work, stress, mood, alcohol and caffeine intake, exercise, diet and any recent illness. Common contributors include:
- Poor or broken sleep, including snoring and pauses in breathing at night, which can point to sleep apnoea
- Low mood, anxiety or ongoing stress
- Recovery from a viral illness
- Hormonal changes, including perimenopause
- Side effects of some medicines
- Heavy periods, which can lead to low iron
Blood tests help to rule medical causes in or out. They are one part of the picture, not the whole answer.
Which blood tests are worth doing?
NHS guidance on investigating tiredness suggests a focused set of tests, chosen according to your symptoms. These commonly include:
The core tests
- Full blood count: checks for anaemia and signs of infection or other blood problems
- Ferritin: a measure of your iron stores, which can be low before anaemia develops
- Thyroid function: an underactive thyroid is a common, treatable cause of tiredness
- HbA1c or glucose: to check for diabetes or raised blood sugar
- Kidney function and liver function
- Inflammatory markers: such as CRP, which can point towards inflammation or infection
- Calcium
Tests that depend on your symptoms
- Coeliac screening if you have bloating, diarrhoea, weight loss or anaemia
- Vitamin B12 and folate if the blood count suggests it, or if you have tingling, a sore tongue, a restricted diet or a digestive condition
- Vitamin D if you have bone or muscle aches, or are at higher risk of deficiency
- A muscle enzyme test if you have muscle weakness or pain
Whether you are local or looking for health screening in Birmingham more widely, choosing tests this way gives you useful answers without a long list of results that are hard to interpret.
Related readingWhat a private health screen does and does not tell youRead the article →Which tests are not worth paying for?
More tests do not always mean better care. Large panels of dozens of markers often throw up small abnormalities that mean nothing, which can lead to worry and further tests. We would generally not recommend:
- Tests for so-called adrenal fatigue, which is not a recognised medical diagnosis
- Food intolerance blood tests that measure certain antibodies, which do not reliably identify intolerances
- Hair mineral analysis
- Repeating tests that were normal recently, without a new reason
Our post on what a private health screen does and does not tell you goes into this in more detail.
Dr Saptarshi’s Note
Most people who come to me exhausted hope one blood test will hold the answer. Sometimes it does. More often, the tests rule out the treatable causes, and the real work is listening to how you sleep, eat, work and feel, and building the picture from there.
Dr Saptarshi SahaMBBS, FRCGP · GP and Co-founder
What if my blood tests are normal?
This is very common, and it is useful information. A normal set of results rules out several conditions and lets us focus on other causes, such as sleep, mood, stress, hormones or lifestyle. It does not mean your tiredness is not real.
From there, a doctor might suggest a sleep assessment, look at your mood more closely, review your medicines, or talk through practical changes. For women in their forties, perimenopause is a frequent and often missed cause, and our women’s health service can help with that. If tiredness has lasted many months and is made worse by activity, your doctor may discuss whether it fits a longer-term fatigue condition.
When to see a doctor sooner
Tiredness alongside certain other symptoms needs prompt assessment. Contact your NHS GP soon, or call NHS 111 out of hours, if you are tired and also have:
- Unexplained weight loss
- Drenching night sweats or a persistent fever
- A new lump or swollen glands
- Unusual bleeding or bruising, blood in your poo or dark black poo
- Extreme thirst and passing a lot of urine
- Breathlessness that is new or getting worse
Call 999 if you have chest pain, severe breathlessness, or you collapse. If low mood is making you feel hopeless, or you have thoughts of harming yourself, please speak to someone today: call NHS 111 and choose the mental health option, contact Samaritans on 116 123, or call 999 in an emergency.
This list is not exhaustive. If you are not sure about something, see a doctor.
How we approach this at Aarva
You see a doctor first. At your appointment Dr Saptarshi Saha, a GP since 2007, will take a full history, examine you where needed, and agree which blood tests make sense for you, rather than offering a standard package. Results are reviewed by a doctor and explained to you in plain language.
Your plan is agreed with the doctor in the appointment, and any tests are priced before they are taken. If the answer lies elsewhere, such as with your NHS GP or a specialist, we will tell you. You can read about what to expect at your appointment, meet our doctors, or see how private GP care and health screening work at Aarva. If you are weighing up whether to go privately at all, our guide to when a private GP appointment makes sense may help.
Questions patients ask
Can I just order a tiredness blood test panel online?
You can, but results without a medical history are hard to interpret. A doctor can choose the tests that fit your symptoms and explain what the results mean for you, which is where most of the value lies.
How quickly will I get my results?
Most routine blood results are back within a few working days. A doctor reviews them and talks you through what they mean and what happens next.
Should I get my vitamin D checked if I am tired?
Not always. Vitamin D testing is most useful if you have bone or muscle aches or are at higher risk of deficiency. Many people in the UK are advised to take a vitamin D supplement in autumn and winter anyway.
My blood tests were normal. Does that mean nothing is wrong?
It means several common medical causes are less likely. Tiredness is still real, and a doctor can help you look at sleep, mood, stress, hormones and other factors that blood tests do not show.
If tiredness is affecting your work, family life or mood, book a consultation with a doctor, or use find your starting point to see which appointment is right for you.
This article is general information and does not replace a consultation with a doctor.
