A 60-year-old woman with diabetes mellitus presented to the emergency department (ER) with complaints of lower limb weakness, preceded by diarrhea. She complained of sweating and palpitations. There was no fever, cough, trauma, seizures, or headache. There was global weakness in all four limbs with absent reflexes and hypotonia. Examination of cranial nerves, the sensory system, and other systems was normal. Guillain-Barre syndrome (GBS) was suspected, but due to the patient's co-morbidities, treatment was withheld for 24 hours and the patient was kept under observation. Medical consultation was sought and thyroid function tests were ordered which showed thyroid-stimulating hormone (TSH) 0.019 uIU/ml (normal: 0.35-4.94 uIU/ml), free triiodothyronine (T3) 11.94 pg/ml (normal: 2.0-4.4 pg/ml), and free thyroxine (T4) >5 ng/dl (normal: 0.70-1.48 ng/dl). Thyroid storm was suspected and she was treated with hydrocortisone, propylthiouracil, Lugol iodine, and beta-blocker and her symptoms improved in 10 days with resolution of the weakness, confirming the diagnosis. Besides highlighting this association, this report demonstrates the importance of conducting thyroid function tests in patients presenting with axonal neuropathy. In patients having weakness in all four limbs and presenting with multiple comorbidities, we need to exclude medical reasons before starting treatment for GBS, such as in our case where it was thyrotoxicosis.