A 42-year-old woman has noticed dry skin, fatigue, and weight gain over the past 3 months. Her blood pressure is 110/70 mm Hg, pulse 60/min, and heart and lungs are normal. Her skin feels rough and dry, but the rest of her examination is normal. Her biochemistry is normal, but the TSH is 39 mU/L. Provide at least 3 possible differential diagnoses and justify your rationale. Develop therapeutic plan options for each diagnosis based on quality, evidence-based clinical guidelines. References should be within last 3 years, peer reviewed, no webMD or Wikapedia. This is a case study so the plans should be specific instead of generalizations.