A 50-year-old male presents to the outpatient clinic with complaints of muscle weakness, fatigue, and palpitations. He reports that these symptoms have gradually worsened over the past two weeks. He has a medical history of hypertension and has been taking a thiazide diuretic for blood pressure control. He also mentions having a low appetite and experiencing increased thirst.

On examination, the patient appears slightly dehydrated and has a weak grip strength in both hands. Vital signs reveal a blood pressure of 130/85 mmHg, a heart rate of 102 beats per minute, and a respiratory rate of 18 breaths per minute. An electrocardiogram (ECG) shows flattened T-waves and U-waves, suggesting potential electrolyte imbalances.

Laboratory tests reveal a serum potassium level of 2.9 mEq/L, along with normal serum sodium and chloride levels. Given his clinical presentation and laboratory results, the patient is diagnosed with hypokalaemia, likely due to the thiazide diuretic use.

The patient is started on oral potassium supplementation and advised to increase dietary potassium intake through foods such as bananas, oranges, and spinach. He is also instructed to monitor for any new symptoms, and a follow-up appointment is scheduled in one week to reassess his potassium levels and overall health. Additionally, the patient's diuretic therapy is reviewed to consider alternative options that may have a lesser impact on his potassium levels.