Hypotension in Multinodular Non-Toxic Goiter is NOT Caused by the Thyroid

The multinodular non-toxic goiter with normal TSH is not causing this patient's hypotension—you must look elsewhere for the cause. 1

Why the Thyroid is Not the Culprit

Normal TSH definitively excludes thyroid dysfunction as the cause of systemic symptoms like hypotension. The American College of Radiology explicitly states that all causes of hypothyroidism would show elevated (not normal) TSH, and there is no role for thyroid imaging in the workup when TSH is normal 1
Non-toxic multinodular goiter, by definition, means euthyroid status. These patients are biochemically euthyroid with normal TSH levels and do not develop systemic manifestations like hypotension from the goiter itself 2, 3, 4
The goiter causes only local mechanical symptoms, not systemic hemodynamic effects. Multinodular goiters produce obstructive symptoms such as dyspnea, orthopnea, dysphagia, and dysphonia through mass effect on the trachea or esophagus—not hypotension 5, 2

You must systematically evaluate for the true causes of hypotension in this patient:

Acute myocardial ischemia, arrhythmias (particularly atrial fibrillation), and heart failure are common precipitants of hypotension. These should be prioritized in your workup 5
Medication effects from negative inotropic drugs (verapamil, diltiazem, beta-blockers) or excessive antihypertensive therapy can cause hypotension 5

Adrenal insufficiency is a critical diagnosis not to miss. Patients may present with fatigue and hypotension; morning cortisol and ACTH testing (ideally around 8 AM) or cosyntropin stimulation testing is essential 5
Hypophysitis can present with hypotension due to secondary adrenal insufficiency. Look for low free T4 with low/normal TSH (not elevated TSH), headache, and other pituitary hormone deficiencies. This requires MRI of the sella with pituitary cuts 5

Volume depletion from excessive diuresis, poor oral intake, or gastrointestinal losses 5
Sepsis or infection increases metabolic demands and causes cytokine-mediated myocardial depression 5
Pulmonary embolism should be considered, as patients with chronic illness are hypercoagulable 5
Medication nonadherence or recent medication changes, including NSAIDs, steroids, or over-the-counter agents 5

The fatigue in this patient is also not thyroid-related given the normal TSH. 1

Evaluate for emotional distress, sleep disturbance, pain, cardiac disease, anemia, and medication effects as these are far more likely causes of fatigue when TSH is normal 1
Screen for other medical conditions unrelated to the thyroid that commonly cause fatigue, as the normal TSH effectively rules out thyroid dysfunction 1

Do not attribute systemic symptoms to the multinodular goiter when TSH is normal. The goiter requires evaluation only for:

Malignancy risk through ultrasound and FNA of suspicious nodules (microcalcifications, irregular borders, central hypervascularity) 1, 4
Local compressive symptoms if present 5, 2
Development of autonomous function (which would manifest as suppressed TSH, not normal TSH) 6, 4