Common causes of fatigue

Fatigue is more than feeling ready for bed: it can involve low energy, reduced concentration, slower thinking, or difficulty managing ordinary tasks. A recent change may follow a viral illness such as COVID-19, not drinking enough fluids, disrupted sleep, or sustained work and caring pressure. Persistent tiredness can also occur with conditions such as Anaemia, Coeliac Disease, Chronic Kidney Disease, or Chronic Fatigue Syndrome. Alcohol Use Disorder and Burnout can affect sleep, mood, and energy as well. The pattern matters: note when fatigue began, whether rest helps, and any associated weight change, breathlessness, pain, fever, low mood, or changes in appetite.

Keep a simple record of sleep, meals, fluids, activity, medicines, and the times your energy dips. Aim for a steady sleep routine, regular nourishing meals, gentle movement within your limits, and adequate fluids. Avoid using alcohol as a sleep aid, and do not stop prescribed medicine without advice. If fatigue continues, worsens, or interferes with work, driving, or self-care, arrange a GP Consultation. A clinician may ask about sleep, mood, bleeding, diet, recent infection, and other symptoms before deciding whether examination or blood tests are useful.

Seek urgent help for fatigue with severe breathlessness, chest pain, fainting, new confusion, marked weakness, or signs of serious dehydration such as inability to keep fluids down. Arrange prompt medical advice for unexplained fatigue that is persistent, rapidly worsening, or accompanied by bleeding, repeated fever, swollen glands, or major changes in mood. The symptom alone does not identify one diagnosis; urgency depends on the wider pattern and how unwell you feel.

Ask: What causes fit my symptoms and timeline? Could sleep, mood, diet, bleeding, medicines, or a recent infection be contributing? Which symptoms should prompt earlier review? Would an examination or blood tests help clarify the cause?