Fatigue

Fatigue means a sustained sense of physical or mental exhaustion that doesn't improve with normal rest. It is the single most common reason patients see a primary-care doctor, and the differential is enormous — from short-term sleep debt to undiagnosed cancer. The clinical approach is built around finding the cause that lab work can address quickly: anaemia, thyroid disorders, B12 / vitamin D deficiency, undiagnosed diabetes, kidney or liver disease. Roughly half of patients seen for fatigue in primary care have a lab-detectable explanation.

• Iron-deficiency anaemia — by far the leading cause in pre-menopausal women.
• Hypothyroidism — fatigue is the most common presenting symptom.
• Vitamin B12 or folate deficiency — common with metformin use, vegan diets, gastric surgery, age >60.
• Vitamin D deficiency — overlap with mood symptoms and musculoskeletal pain.
• Undiagnosed type 2 diabetes — post-prandial fatigue is a classic early symptom.
• Chronic kidney disease — rising creatinine, falling eGFR.
• Depression, sleep apnoea, chronic infection — non-lab causes that still need consideration.

A focused fatigue panel usually starts with: CBC (haemoglobin, MCV), ferritin, TSH, HbA1c, vitamin D, B12, comprehensive metabolic (creatinine + ALT). Mediora.AI interprets each marker in context and surfaces the highest-likelihood explanation for your specific pattern.