Book PTH Test: Purpose, Normal Range and Price

The PTH test, also known as the Intact Parathyroid Hormone test, is a blood test that measures the level of parathyroid hormone, a hormone produced by the four small parathyroid glands located behind the thyroid gland in the neck. PTH is the master regulator of calcium and phosphorus balance in the body. It acts on the bones, kidneys, and intestines to raise blood calcium levels when they fall too low, and is suppressed when calcium levels are adequate or high. The intact PTH assay specifically measures the biologically active full-length form of the hormone, making it the most accurate and clinically relevant PTH measurement available. Disorders of parathyroid function are among the most significant causes of abnormal calcium levels in clinical practice. Overactive parathyroid glands, known as hyperparathyroidism, cause persistently elevated calcium leading to kidney stones, bone loss, fatigue, depression, and gastrointestinal symptoms. Underactive parathyroid glands, known as hypoparathyroidism, cause dangerously low calcium levels resulting in muscle cramps, tetany, seizures, and cardiac arrhythmias. In India, Vitamin D deficiency is extremely prevalent and is one of the most common causes of secondary hyperparathyroidism, where chronically low calcium drives the parathyroid glands to overproduce PTH. The test involves a simple blood draw completed in under five minutes, ideally collected in the fasting state in the morning.

Doctors prescribe a PTH test in the following situations: Investigating hypercalcaemia, abnormally high blood calcium, where PTH measurement is the critical first step in distinguishing primary hyperparathyroidism, the most common cause in outpatient settings, from malignancy-associated hypercalcaemia where PTH is typically suppressed. Diagnosing primary hyperparathyroidism in patients with kidney stones, osteoporosis, fatigue, depression, abdominal pain, and polyuria where an elevated PTH alongside elevated calcium confirms autonomous overproduction from a parathyroid adenoma or hyperplasia. Investigating hypocalcaemia, abnormally low blood calcium, where a low PTH alongside low calcium confirms hypoparathyroidism, most commonly occurring after thyroid or parathyroid surgery, while a high PTH with low calcium indicates secondary hyperparathyroidism from Vitamin D deficiency or chronic kidney disease. Evaluating secondary hyperparathyroidism in patients with chronic kidney disease, where impaired phosphate excretion and reduced Vitamin D activation by the kidneys chronically stimulate the parathyroid glands, leading to elevated PTH that contributes significantly to renal osteodystrophy and cardiovascular complications. Monitoring patients with chronic kidney disease on dialysis where PTH is a critical component of the CKD-mineral and bone disorder assessment guiding treatment with Vitamin D analogues, phosphate binders, and calcimimetics. Investigating osteoporosis, particularly in younger patients or those with atypical bone loss patterns, where elevated PTH from primary or secondary hyperparathyroidism is a correctable and frequently overlooked cause of accelerated bone density loss. Post-operative monitoring after parathyroid or thyroid surgery where a rapid fall in intraoperative or post-operative PTH confirms successful removal of the overactive gland and guides the decision to administer calcium supplementation.

The PTH test measures the concentration of intact parathyroid hormone in the blood, reported in picograms per millilitre (pg/mL) or nanograms per litre (ng/L), which are equivalent units. Normal PTH Range in India The standard reference ranges used across most Indian diagnostic laboratories and endocrinology centres are as follows. For adults, a normal intact PTH level is between 15 and 65 pg/mL. Values may vary slightly between laboratories depending on the immunoassay platform used. Interpreting PTH Results An elevated PTH above 65 pg/mL alongside elevated calcium confirms primary hyperparathyroidism, where overactive parathyroid glands autonomously produce excess PTH independent of calcium regulation. This is the most common cause of hypercalcaemia in ambulatory patients and requires specialist endocrinological or surgical evaluation. An elevated PTH above 65 pg/mL alongside low or normal calcium indicates secondary hyperparathyroidism, most commonly caused by Vitamin D deficiency, calcium malabsorption, or chronic kidney disease, where the parathyroid glands are responding appropriately to chronically low calcium stimulation. Treatment targets the underlying cause rather than the parathyroid glands directly. A low PTH below 15 pg/mL alongside low calcium confirms hypoparathyroidism, most commonly following thyroid or parathyroid surgery, and requires calcium and Vitamin D replacement therapy. A suppressed PTH alongside elevated calcium raises strong concern for malignancy-associated hypercalcaemia and requires urgent oncological investigation.

Fasting for 8 to 12 hours before the test is recommended as PTH levels can be transiently influenced by food intake, particularly calcium-rich meals. The sample is ideally collected in the morning. You may drink water normally during the fasting period. Our team confirms preparation requirements at the time of booking. PTH is highly unstable in blood samples and degrades rapidly at room temperature. It is critical that the sample is collected into the correct tube, kept on ice or refrigerated immediately after collection, and transported to the laboratory within the shortest possible time. SecondMedic's phlebotomists are specifically trained to handle PTH samples correctly to ensure accurate results. Inform the phlebotomist about all medications you are currently taking, particularly calcium supplements, Vitamin D, cinacalcet, bisphosphonates, thiazide diuretics, and lithium, as all of these directly influence PTH levels and must be disclosed for accurate interpretation. Avoid calcium supplement intake on the morning of the test unless specifically advised by your doctor, as a recent calcium dose transiently suppresses PTH and may mask a true elevation. Stay normally hydrated before sample collection.

If you are booking through the SecondMedic platform the PTH test price starts at approximately Rs. 1,580. The exact price will be confirmed at the time of booking through SecondMedic. If your doctor has prescribed multiple tests alongside PTH, SecondMedic health packages include PTH as part of a broader calcium metabolism, bone health, or endocrine panel at a significantly lower combined price.

SecondMedic provides home sample collection for PTH test across all major areas in India. You do not need to visit a lab or collection centre. A certified and trained phlebotomist comes to your home or workplace at your chosen time, collects the sample using sterile single-use equipment with correct cold-chain handling, and ensures it is transported to the NABL-accredited lab within the required time window for accurate processing. Please note that SecondMedic provides free home sample collection on all tests priced above Rs. 300. Our team will check your pincode and confirm if your address falls under our free sample collection eligibility criteria, which depends upon the lab location and phlebotomist availability. Home collection is available between 7 AM and 10 PM, seven days a week, including Sundays and public holidays. Enter your pincode on the booking page or call our helpline to confirm availability at your address.