“I’m constantly hungry and thirsty, weeing all the time, losing weight despite eating loads, and I’m exhausted”

POLYPHAGIA (increased appetite/constant hunger) with the OSMOTIC symptoms of hyperglycaemia — POLYDIPSIA (thirst), POLYURIA (excess urination), unexplained WEIGHT LOSS despite eating, and fatigue — is the classic cluster of new DIABETES, commonly TYPE 2 in an overweight, middle-aged patient with family history, though TYPE 1/LADA must be considered — NICE NG17 features are ketosis, rapid weight loss, age under 50, BMI below 25 and autoimmune history, and age or BMI alone must not exclude it. Critically, screen for and exclude acute decompensation/DIABETIC KETOACIDOSIS — being very unwell, vomiting, abdominal pain, drowsiness/confusion, deep rapid (Kussmaul) breathing, ketotic ("pear-drop") breath and dehydration — which is a medical emergency needing same-day assessment/admission (especially if type 1 is suspected), so check capillary glucose AND ketones. Confirm the diagnosis appropriately (capillary glucose and ketones now; laboratory fasting plasma glucose ≥7.0 / random ≥11.1 with symptoms; HbA1c ≥48 mmol/mol only where appropriate), noting that in a symptomatic patient one diagnostic test suffices and that WHO 2011 (international) advises against HbA1c for diagnosis when symptoms are under two months or type 1 is suspected (use plasma glucose). Where the picture is atypical or glucose normal, differentiate other causes of polyphagia with weight loss — hyperthyroidism (TFTs), malignancy, malabsorption — but the osmotic symptoms strongly point to diabetes. For confirmed type 2 diabetes, initiate management per NICE NG28 (lifestyle, modified-release metformin then an SGLT2 inhibitor with DKA counselling, renal considerations, structured education), cardiovascular-risk management (NICE NG238 atorvastatin 20 mg if QRISK 10% or more), complication screening — retinal, foot, renal/ACR — and DVLA advice, and refer urgently/admit if DKA or type 1 is suspected. Safety-net for deterioration. NICE NG12: new-onset diabetes with weight loss at 60 or over prompts urgent pancreatic imaging — not applicable at 48, but reassess weight loss that continues after glucose control.