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Always tired? Common causes of low energy and fatigue

Feeling tired all the time is one of the most common reasons people see a doctor. Most causes are common and treatable once found.

Common causes

  • 01Not enough sleep, or a sleep disorder such as sleep apnoea
  • 02Low mood or depression
  • 03Iron-deficiency anaemia
  • 04Underactive thyroid
  • 05Diabetes or high blood sugar
  • 06Vitamin B12 deficiency, side effects of medicines, and very low activity

Iron loss from periods makes anaemia a leading suspect in women.

As you get older. Thyroid problems, diabetes and anaemia become more common with age.

What a doctor may check

A doctor may check a full blood count, ferritin, thyroid (TSH), blood sugar (HbA1c), and B12 if you are at risk.

When to see a doctor

See a doctor soon if tiredness is severe or getting worse, or comes with weight loss, fever, night sweats, breathlessness or blood in your stool.

This page is general information, not a diagnosis. Venva's content is written against clinical guidelines and systematic reviews, listed below. See our medical disclaimer.

References

  1. 1.Iron-deficiency anemia. New England Journal of Medicine, 2015.doi:10.1056/NEJMra1401038
  2. 2.Hypothyroidism. The Lancet, 2017.doi:10.1016/S0140-6736(17)30703-1
  3. 3.Vitamin B12 deficiency. Nature Reviews Disease Primers, 2017.doi:10.1038/nrdp.2017.40

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