Why am I so tired?

Feeling tired is common and can often be explained by the demands of our busy lives. However, feeling tired, fatigued or exhausted most or all of the time can sometimes be a sign of an underlying medical problem. Our tiredness tests will look for some of the most common conditions that can cause fatigue.

Which tests are included?

Thyroid: an underactive thyroid can result in feeling tired, sluggish and having a low mood. This test includes measurement of three hormone: Thyroid stimulating hormone (TSH), free thyroxine (FT4) and free triiodothyronine (FT3). More detailed information can be found on our thyroid test page

Diabetes: One of the common signs experienced by people with diabetes is feeling fatigued or exhausted. This test measures glycated haemoglobin also known as HbA1c. This is a measure of the amount of sugar (glucose) in the blood over the previous 2-3 months. More detailed information can be found on our diabetes test page

Anaemia: Anaemia is a low level of haemoglobin in the blood. Tiredness, lacking in energy, feeling breathless after exercise and feeling faint can all be signs of anaemia. This test measures haemoglobin, red blood cell count and will also look for some of the most common causes of anaemia: iron, vitamin B12 or folate deficiency. More detailed information can be found on our anaemia test page.

Other causes of tiredness

Tiredness can be due to lots of different factors including stress, anxiety, exercise, caffeine, alcohol, hydration, diet, regularity of meals and sleeping patterns. The NHS has a useful website offering self-help tips to fight tiredness. You should make an appointment with your doctor if you have been tired or fatigued for more than four weeks or if you feel that you have overwhelming tiredness that does not improve with sleep.

Please note: these tests are available for people aged over 18 only. Please collect and post your sample to us Monday-Thursday, to avoid delays over the weekend. In a small number of cases, it may not always be possible to provide a result, please see our terms and conditions for details.