Hypothyroidism Symptoms Checklist: From Fatigue to Myxedema

Hypothyroidism manifests across multiple systems due to global metabolic slowing.

Common Symptoms

• Fatigue, lethargy, excessive sleepiness
• Weight gain (modest), difficulty losing weight
• Cold intolerance
• Dry, cool skin; brittle hair and nails
• Constipation
• Muscle weakness, cramps, carpal tunnel syndrome
• Menstrual irregularities (heavy, irregular)
• Depression, anxiety, memory impairment, "brain fog"
• Joint pain, stiffness
• Puffy face, periorbital edema
• Bradycardia, diastolic hypertension
• Elevated LDL cholesterol
• Goiter (if iodine deficiency or Hashimoto's)

Severe: Myxedema Coma

• Hypothermia, obtundation, hypotension, respiratory depression, hyponatremia
• Precipitants: infection, sedatives, cold exposure, trauma
• Mortality 20–50% — requires ICU, IV thyroid hormone, steroids, support.

Epidemiology and Cause

• Women 5–8x more likely; peak incidence >50 years.
• Hashimoto's thyroiditis (autoimmune) is #1 cause in iodine-sufficient areas.
• Other: post-radioiodine, post-thyroidectomy, medications (lithium, amiodarone), iodine deficiency.

Treatment

Levothyroxine monotherapy; individualized dosing; lifelong for most. Symptoms improve in weeks; lipids normalize in months.