Thyroid and fatigue: is your thyroid the cause?

Persistent fatigue is one of the most common reasons to have your thyroid checked. And fairly so: an underactive thyroid can leave you drained. Yet the thyroid is only one of the possible causes, and often not the first. In our experience, people sometimes carry fatigue for months while a simple blood test could have pointed a direction sooner (Chaker 2017).

This article belongs to the overview about your thyroid and focuses on the link with fatigue.

Can your thyroid cause fatigue?

Yes, it can. With an underactive thyroid your metabolism runs slower, which can show as tiredness and a sluggish feeling. A mildly raised TSH is sometimes linked to fatigue too, though the link is not equally strong for everyone (Biondi 2019). Fatigue is a non-specific symptom, so it does not prove a thyroid problem on its own.

Which other causes of fatigue are there?

A low ferritin or low vitamin D can cause surprisingly similar symptoms to an underactive thyroid.

Which blood values to test?

To rule the thyroid in or out, start with TSH, optionally free T4. Read more about your TSH level, the broader always tired overview, or the underactive thyroid.

What if your thyroid is normal?

If your TSH is normal, a thyroid problem is less likely, but your symptoms are not gone. Then it helps to look further at iron, vitamin D, sleep and stress. You can have a thyroid function test at Vitalcheck, and discuss the pattern with your GP.

References

• Chaker L, et al. Hypothyroidism. Lancet. 2017. PMID: 28336049.
• Biondi B, Cooper DS. Subclinical Hypothyroidism: A Review. JAMA. 2019. PMID: 31287527.
• Thuisarts.nl. Ik ben moe.

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