Fatigue blood test to explore the cause of your symptoms

Being tired is one of the most common complaints there is, which is exactly why it can be hard to pin down. It can be linked to your sleep, a busy period or your lifestyle, but sometimes there is also something at play that shows up in your blood.

A blood test for tiredness can bring a few of those possible causes into view, such as a low iron store, a thyroid that works differently than usual, or a shortage of certain vitamins. It gives you something concrete to hold on to, instead of guessing where your energy is going.

This test may be for you if you have felt tired, listless or worn out for a while and want to know whether something in your blood is involved. Many women recognise this feeling, for example during a hectic period, after a pregnancy or during their reproductive years.

Because women who menstruate can more often have a lower iron store, and thyroid issues are relatively common in women, this panel can be especially relevant for them. If you are unsure where your fatigue comes from, a measurement can give you a first direction.

This panel measures a number of markers that are often linked to tiredness:

• Ferritin: reflects your iron store, which when low can go together with fatigue.
• Complete Blood Count (CBC): looks at your red and white blood cells and can point to anaemia, among other things.
• TSH (Thyroid Stimulating Hormone): the hormone that steers your thyroid and can indicate how active it is.
• Free T4 (Thyroxine): a thyroid hormone that, together with TSH, gives a picture of your thyroid function.
• Free T3 (Triiodothyronine): the active thyroid hormone that helps drive your metabolism.
• Vitamin B12: involved in your energy metabolism and in the production of red blood cells.
• Vitamin D (25-OH): a vitamin that many people run low on, especially during the winter.
• Glucose (Fasting): your fasting blood sugar, which offers a clue to how your body handles sugar.
• HbA1c (Glycated Hemoglobin): gives an impression of your average blood sugar over the past two to three months.

A tiredness test can give you insight into a number of factors that may be connected to your energy. You can see, for example, whether your iron store is on the low side, whether your thyroid values fall within the usual range, and how your vitamin B12 and vitamin D are doing.

Your blood sugar is also included, which sometimes plays a role in how fit you feel. Important to know: these results are individual data points, not a diagnosis. They can, however, help you take a step further together with your GP in the search for an explanation.

This test requires a small blood draw at a certified blood collection point. In the Netherlands you can choose from 700+ locations, so there is often one near you.

After ordering, you pick a location and schedule a moment that suits you. The draw itself usually takes only a few minutes, and you do not need a referral from your GP.

A blood test when you feel tired can be valuable at different moments, for example:

• when you have felt unexplainably tired for weeks or months
• when, alongside fatigue, you also notice you get out of breath more quickly or look pale
• when you suspect your thyroid or your iron may play a role
• when you simply want a factual starting point before talking to your GP

Some people choose to test periodically to keep an eye on these values.

You may be wondering which blood values are relevant when you feel tired. In your result you see your own value per marker, together with a reference range and a short explanation. What counts as usual can vary slightly by laboratory.

A value below or above the range does not immediately mean something is wrong. A low ferritin can fit with a reduced iron store, while an unusual TSH may point to something in your thyroid. The doctor helps you place your values in the right context.

Your result is usually available online within a few working days. Each value is shown clearly with a reference range and an explanation, so you understand what you see.

Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.