What is the Parathyroid Hormone test?

The Parathyroid Hormone (PTH) blood test measures the level of PTH, a hormone produced by the parathyroid glands that plays a central role in regulating calcium, phosphorus, and vitamin D metabolism.

PTH acts on bones, kidneys, and the digestive system to maintain stable calcium levels in the blood. Even small changes in PTH can significantly affect bone strength, nerve function, and muscle activity.

This test is commonly used alongside calcium, vitamin D, phosphate, and kidney function tests to assess parathyroid gland activity and overall mineral balance.

Why do I need a test for Parathyroid Hormone?

PTH testing is essential when investigating abnormal calcium levels or symptoms related to bone and mineral imbalance. It helps determine whether calcium abnormalities are caused by parathyroid dysfunction or other underlying conditions.

The test is particularly useful for diagnosing hyperparathyroidism, hypoparathyroidism, vitamin D–related disorders, and chronic kidney disease–related mineral imbalance.

You may benefit from this test if you experience:

• Bone pain or bone weakness

• Recurrent kidney stones

• Muscle cramps or spasms

• Fatigue or weakness

• Tingling or numbness in fingers or lips

• Abnormal calcium or phosphate levels

• Osteoporosis or fracture risk

• Suspected parathyroid gland disorders

Benefits of the Parathyroid Hormone test

1. Evaluates parathyroid gland function
   Helps identify overactive or underactive parathyroid glands.

2. Assesses calcium balance
   Clarifies the cause of high or low calcium levels.

3. Supports bone health assessment
   Abnormal PTH levels can significantly affect bone density.

4. Aids diagnosis of hyperparathyroidism
   Essential for identifying primary and secondary forms.

5. Supports kidney disease monitoring
   Useful in assessing mineral imbalance in chronic kidney disease.

6. Complements vitamin D testing
   Helps interpret calcium and vitamin D interactions.

7. Guides clinical decision-making
   Supports appropriate follow-up and management strategies.

8. Useful in osteoporosis evaluation
   Helps determine hormonal contributions to bone loss.

Step-by-step – how we offer Parathyroid Hormone testing

Clinic-based testing (UK-wide)

• Choose your nearest UK clinic

• Attend your appointment

• A qualified clinician or phlebotomist collects your blood sample

• Sample is sent to the laboratory for analysis

At-home or hotel testing (+£60)

• A qualified phlebotomist visits your home or hotel

• Blood sample collected in a comfortable, familiar setting

• No clinic visit or travel required

Both services are available UK-wide.

Your Parathyroid Hormone results explained

Low PTH levels

Low parathyroid hormone levels indicate reduced parathyroid gland activity, which may lead to low blood calcium levels. This can affect nerve and muscle function and may cause symptoms such as tingling, muscle cramps, or spasms.

Low PTH may occur after neck surgery, in autoimmune conditions, or due to magnesium imbalance.

UK reference range:

• Low: <1.6 pmol/L

Normal PTH levels

Normal PTH levels indicate appropriate parathyroid regulation of calcium balance. When calcium and vitamin D levels are also normal, this suggests stable bone and mineral metabolism.

Symptoms may still occur if other related markers are abnormal.

UK reference range:

• Normal: 1.6–6.9 pmol/L

High PTH levels

High PTH levels suggest increased parathyroid activity and are commonly associated with hyperparathyroidism. This may lead to elevated calcium levels, bone demineralisation, and kidney stone formation.

High PTH can also occur secondary to vitamin D deficiency or chronic kidney disease.

UK reference range:

• High: >6.9 pmol/L