What Is PTH (Parathormone)? Causes, Symptoms, and Management of High and Low PTH Levels

 

Introduction

🧠Parathyroid Hormone (PTH), also known as Parathormone, is a key regulator of calcium, phosphate, and vitamin D metabolism. Secreted by the small parathyroid glands located behind the thyroid, this hormone ensures that calcium levels in the blood remain within a narrow, healthy range—vital for bone strength, nerve function, and muscle activity.

Abnormal PTH levels can signal endocrine or metabolic disorders, including hyperparathyroidism, hypoparathyroidism, chronic kidney disease, or vitamin D deficiency. Understanding what PTH does and how imbalances affect your body is crucial for maintaining long-term metabolic and bone health.

---

🧬 What Is Parathyroid Hormone (PTH)?

Parathyroid hormone (PTH) is a protein hormone produced by the parathyroid glands. Its main role is to increase blood calcium levels when they fall too low. It achieves this by:

• Stimulating calcium release from bones
• Enhancing calcium reabsorption by the kidneys
• Activating vitamin D, which boosts calcium absorption in the intestines
• Reducing phosphate reabsorption in the kidneys

These combined actions help maintain bone structure, muscle contractions, and nerve signaling.

---

📊 Normal Range of PTH

Parameter	Typical Range
Parathyroid Hormone (PTH)	10–65 pg/mL (varies by lab)

---

⚠️ Causes of High Parathyroid Hormone (PTH)

Elevated PTH, or hyperparathyroidism, can be classified as:

1. Primary Hyperparathyroidism:
   Caused by a benign parathyroid tumor (adenoma) or gland enlargement.
2. Secondary Hyperparathyroidism:
   Occurs due to vitamin D deficiency or chronic kidney disease—the glands overwork to maintain calcium balance.
3. Tertiary Hyperparathyroidism:
   Develops after prolonged secondary hyperparathyroidism when the glands become permanently overactive.

Other causes include:

• Long-term lithium or thiazide diuretic use
• Genetic predisposition
• Chronic vitamin D deficiency
• Malabsorption syndromes

---

⚕️ Symptoms of High PTH (Hyperparathyroidism)

Persistent high PTH leads to excess calcium in the blood (hypercalcemia), resulting in:

• Bone pain, fractures, or osteoporosis
• Fatigue and muscle weakness
• Frequent urination and kidney stones
• Nausea, constipation, or abdominal pain
• Depression, anxiety, or confusion
• Hypertension and cardiovascular risk

---

📉 Causes of Low Parathyroid Hormone (PTH)

Low levels, or hypoparathyroidism, typically result from:

• Surgical removal or injury to parathyroid glands (after thyroid surgery)
• Autoimmune destruction of the glands
• Magnesium deficiency
• Genetic disorders affecting gland development

---

⚠️ Symptoms of Low PTH (Hypoparathyroidism)

When PTH levels are too low, calcium drops and phosphate rises, causing:

• Muscle cramps or spasms (tetany)
• Tingling or numbness in hands, feet, or face
• Seizures or fainting episodes
• Dry skin, brittle nails, or hair loss
• Cognitive issues like anxiety or irritability

---

🔍 How PTH Is Tested and Diagnosed

A PTH blood test is performed alongside:

• Serum calcium, phosphate, and vitamin D tests
• Kidney function tests (creatinine, urea)
• Thyroid ultrasound or sestamibi scan (if an adenoma is suspected)

Interpretation must consider both PTH and calcium levels:

Calcium	PTH	Likely Condition
Normal	Normal	Normal parathyroid function
High	High	Primary hyperparathyroidism
Low	High	Secondary hyperparathyroidism (CKD or Vitamin D deficiency)
High	Low	Malignancy or vitamin D toxicity
Low	Low	Hypoparathyroidism

---

🏥 Treatment and Management

For High PTH (Hyperparathyroidism):

• Surgical removal of overactive glands (parathyroidectomy)
• Calcimimetic drugs (e.g., Cinacalcet) to reduce PTH production
• Vitamin D and calcium balance correction
• Interventional radiology (for non-surgical candidates):
• Radiofrequency Ablation (RFA)
• Microwave Ablation (MWA)
• Embolization or High-Intensity Focused Ultrasound (HIFU)

For Low PTH (Hypoparathyroidism):

• Calcium and vitamin D supplementation
• Synthetic PTH therapy for severe or resistant cases
• Magnesium correction when deficient
• Regular monitoring of calcium, phosphate, and kidney function

---

💡 Complications of PTH Imbalance

• Bone demineralization and osteoporosis
• Kidney stones or calcification
• Cardiovascular disease
• Neurological symptoms from calcium disturbances
• Chronic fatigue and mood changes

---

🧘 Prevention and Lifestyle Tips

To maintain healthy PTH levels:

• Ensure adequate vitamin D through sunlight or supplements
• Eat a balanced diet rich in calcium and magnesium
• Stay hydrated and reduce excess phosphate intake (from soft drinks, processed foods)
• Manage chronic kidney disease proactively
• Exercise regularly for bone and metabolic health

---

📋 Summary

• Parathyroid hormone (PTH) controls calcium and phosphate balance.
• High PTH (hyperparathyroidism) can lead to bone loss, kidney stones, and fatigue.
• Low PTH (hypoparathyroidism) causes low calcium, muscle spasms, and tingling.
• Testing PTH helps detect endocrine and metabolic disorders early.
• Treatment depends on the underlying cause—ranging from supplements to surgery or ablation.
• Healthy nutrition, vitamin D maintenance, and regular checkups are key to prevention.

---

🧠 Frequently Asked Questions (FAQs)

Q1. Why is PTH important?
PTH maintains calcium balance in the blood, supporting strong bones, proper nerve signaling, and muscle contractions.

Q2. What causes high PTH levels?
High PTH usually results from hyperparathyroidism, chronic kidney disease, or vitamin D deficiency.

Q3. What are the symptoms of high PTH?
Bone pain, fatigue, kidney stones, mood swings, and constipation are common.

Q4. How can I lower PTH naturally?
Optimize vitamin D and calcium levels, manage kidney function, and limit phosphate-rich processed foods.

Q5. What happens if PTH is low?
Low PTH causes hypocalcemia, resulting in muscle cramps, tingling, or seizures.

Q6. Is high PTH always due to cancer?
No, over 99% of high PTH cases are due to benign adenomas or vitamin D deficiency, not cancer.

Q7. When is PTH surgery recommended?
If calcium is consistently high, bones are weak, or kidney stones are present, parathyroidectomy may be advised.

Q8. How often should PTH be checked?
People with thyroid surgery, vitamin D deficiency, or kidney issues should check PTH every 6–12 months.

---