Meet the patient before the appointment begins.

Provisional order by support in this record—not calibrated probabilities. Possibilities 2–4 have important missing tests; no result here independently rules them in or out.

1. 1Hashimoto-related thyroid dysfunction

   Why: Documented Hashimoto disease, persistent fatigue and a rising TSH above this laboratory's upper reference limit. Euthyrox was recorded after that result, so this value cannot assess treatment response. Source: thyroid report and medication history.

   Clarifying threshold: Repeat TSH and free T4 after an appropriate interval. Persistent TSH above the laboratory's 4.0 mIU/L upper limit supports further review; interpret alongside free T4, symptoms and treatment timing—not as a stand-alone confirmation.

   Open illustrative thyroid source →
2. 2Iron deficiency, with or without anaemia

   Why: Fatigue is compatible, but this shared case contains no CBC or ferritin result. This is a question to test, not a finding in the record.

   Clarifying threshold: CBC and ferritin. In an apparently healthy adult, ferritin <15 µg/L supports iron deficiency; inflammation and clinical context can change interpretation. A higher result alone does not exclude every cause of fatigue.

3. 3Type 2 diabetes or dysglycaemia

   Why: Father has type 2 diabetes and fatigue is reported. The case has no HbA1c or glucose value, so support is limited. Source: recorded family history.

   Clarifying threshold: HbA1c ≥6.5% or fasting plasma glucose ≥126 mg/dL meets a diagnostic threshold; confirm an abnormal result unless there is unequivocal hyperglycaemia. Values below these cutoffs do not explain the fatigue by themselves.

4. 4Vitamin B12 deficiency

   Why: Fatigue can occur, but no B12 level or related findings are in this record. This ranks last because case-specific support is missing.

   Clarifying threshold: Check serum B12; laboratory lower limits commonly fall near 200–250 pg/mL. If the result is borderline, methylmalonic acid may help, interpreted with renal function and the laboratory method.

It is less consistent with the available thyroid pattern: the source report shows TSH 5.3 mIU/L, above its 0.4–4.0 range, whereas hyperthyroid patterns usually start with TSH below range. The record also documents Hashimoto disease and thyroid replacement. This is a reason to rank Graves' disease lower, not proof that it is impossible. Check symptoms, examination and any new results if the clinical picture suggests it.