Understanding thyroid hormones for the Primary Care NP

Thyroid Hormones 

• the hypothalamus produces TRH (thyrotropin releasing hormone) that acts on the pituitary gland to stimulate the release of TSH (thyroid stimulating hormone)
• TSH then regulated the synthesis and secretion of T4 and T3 by the thyroid gland 
• TSH secretion by the pituitary is regulated by the serum concentration of T4 and T3
• Small increases in serum levels of T4 and T3 results in a decrease in TSH releases, while decreases in T4 and T3 serum concentrations results in an increased secretion of TSH. 

Common causes of hypothyroidism 

• Hashimoto's Disease (chronic autoimmune thyroiditis)
  • most common cause in iodine-sufficient areas of the world 
  • caused by cell and antibody-mediated destruction of thyroid tissue 
  • can be goitrous or atrophic 
  • TPO (thyroid peroxidase antibodies) will be positive 
• thyroidectomy 
• radio-iodine therapy or external irradiation 
• drug induced 

Common causes of hyperthyroidism 

• autoimmune thyroid disease (Grave's disease or Hashitoxicosis) 
• thyroiditis 
• overactive thyroid nodules 
• TSH-producing pituitary adenoma
• excessive thyroid replacement therapy 

Next week, we will go into interpreting thyroid labs in primary care. 

Come back weekly for new blog posts that can be helpful in practice. I'd love to connect- email me at [email protected] or DM me on social! 

Would you benefit from an experienced NP as a mentor to go over lab results with you, talk about difficult cases, or just ask questions/vent? Check out my 1:1 mentor program here and email me at [email protected] to set up a free 15 minute phone call to discuss further.

 Check out all the other blog posts here.