Hyperthyroidism, marked by excess thyroid hormones (T4 and T3), presents with symptoms like palpitations, heat intolerance, anxiety, and weight loss despite a normal or increased appetite. Diagnosis involves low serum TSH levels and elevated free T4 and/or T3. Rarely, hyperthyroidism can lead to nondiabetic ketoacidosis (NDKA). This report describes a 40-year-old woman with palpitations, chest discomfort, heat intolerance, insomnia, and significant weight loss. Laboratory tests showed severely suppressed TSH, elevated free T4 and T3, and high anion gap metabolic acidosis with elevated ketone levels. She was diagnosed with hyperthyroidism-induced NDKA. Hyperthyroidism can promote lipolysis and ketogenesis, potentially leading to NDKA. Though uncommon, it is essential for clinicians to consider hyperthyroidism in NDKA cases when common causes are excluded. Our patient's symptoms significantly improved with propranolol and carbimazole treatment. This case emphasizes the importance of recognizing hyperthyroidism as a potential cause of NDKA. Appropriate diagnosis and treatment with antithyroid medications can lead to complete symptom resolution and normalization of biochemical markers.