Parathyroid Hyperfunction

Authored by Chris McDermott, APRN, practicing with autonomous authority in Florida

Introduction

Parathyroid hyperfunction, medically known as hyperparathyroidism, is a condition where one or more of the parathyroid glands produce excess parathyroid hormone (PTH). This hormonal imbalance disrupts the body’s calcium regulation, leading to elevated calcium levels (hypercalcemia) in the blood. While sometimes silent in its early stages, parathyroid hyperfunction can contribute to significant long-term complications—including osteoporosis, kidney stones, and cardiovascular disease.

At Intercoastal Health, we use a functional medicine nurse practitioner framework to assess parathyroid function, identify contributing factors, and implement personalized strategies that support endocrine balance, bone strength, and renal health. Our goal is to not only correct lab abnormalities but also address the root causes that contribute to hormonal dysregulation and mineral imbalances.

Understanding Parathyroid Hormone and Calcium Regulation

The parathyroid glands are four small endocrine glands located behind the thyroid. Their primary function is to regulate calcium and phosphorus levels in the blood and bones by secreting parathyroid hormone (PTH). When blood calcium levels fall, PTH is released to:

• Stimulate bone resorption, releasing calcium into circulation
  
• Increase calcium reabsorption in the kidneys, reducing urinary loss
  
• Enhance activation of vitamin D, which increases calcium absorption in the intestines
  
  

In hyperparathyroidism, this finely tuned system becomes dysregulated—PTH continues to be secreted even when blood calcium levels are already high, leading to persistent hypercalcemia and abnormal phosphorus and bone metabolism.

Types of Parathyroid Hyperfunction

• Primary Hyperparathyroidism
  
  • Usually caused by a benign adenoma on one gland
    
  • Leads to elevated PTH and calcium levels
    
• Secondary Hyperparathyroidism
  
  • Occurs in response to low blood calcium, often due to chronic kidney disease or vitamin D deficiency
    
• Tertiary Hyperparathyroidism
  
  • Develops after prolonged secondary hyperparathyroidism, especially in end-stage renal disease
    
  • Parathyroid glands become autonomous and continue overproducing PTH even when calcium normalizes

Symptoms of Parathyroid Hyperfunction

Early stages may be vague or absent, but common symptoms include:

• Bone pain or fractures due to mineral loss
  
• Kidney stones (calcium-based)
  
• Fatigue and muscle weakness
  
• Depression, anxiety, or confusion
  
• Abdominal discomfort, nausea, or constipation
  
• Excessive thirst and urination
  
• Memory difficulties or mood changes
  
  

Functional Medicine Diagnostic Approach

Our evaluation is systems-based and biomarker-guided. Key laboratory tests include:

Imaging

• Neck ultrasound or sestamibi scan to localize adenomas
  
• MRI or 4D CT if initial imaging is inconclusive
  
  

Root Causes of Parathyroid Hyperfunction

Identifying “why” is essential:

• Parathyroid adenoma or gland hyperplasia (primary)
  
• Chronic kidney disease or vitamin D deficiency (secondary)
  
• Prolonged secondary hyperparathyroidism leading to tertiary hyperfunction
  
  

Clinical Implications and Related Conditions

Untreated hyperparathyroidism affects multiple systems: