PTH Test Explained: Normal Range, High & Low PTH Levels, Calcium Balance & Bone Health (India 2026) | पैराथायरॉइड हार्मोन टेस्ट गाइड
PTH Test (Parathyroid Hormone) Explained: Normal Range, High & Low PTH Causes (India 2026)
PTH टेस्ट (पैराथायरॉइड हार्मोन): नॉर्मल रेंज, हाई और लो PTH के कारण और कैल्शियम से संबंध
Has your doctor ordered a PTH test alongside your calcium or Vitamin D report? Or did your calcium come back abnormal and now you have been asked to check PTH? Most patients have never heard of the parathyroid glands — yet they perform one of the most critical jobs in your body: keeping blood calcium within the narrow range that keeps your heart beating, nerves firing, and bones intact.
The PTH (Parathyroid Hormone) test is the single most important test for diagnosing the cause of abnormal calcium — both high and low. Without PTH, a calcium result is only half the story. This guide explains what the parathyroid glands are, what PTH does, what the normal range is, and exactly how to interpret PTH alongside calcium. For a foundation on reading lab reports, see our beginner's guide to lab reports.
क्या आपके डॉक्टर ने कैल्शियम या विटामिन D रिपोर्ट के साथ PTH टेस्ट करवाने को कहा है? पैराथायरॉइड हार्मोन (PTH) वह परीक्षण है जो असामान्य कैल्शियम का कारण बताता है। इसके बिना कैल्शियम रिपोर्ट अधूरी है। यह गाइड PTH के बारे में सब कुछ सरल भाषा में समझाती है।What Are the Parathyroid Glands? / पैराथायरॉइड ग्रंथियां क्या हैं?
Despite the similar name, the parathyroid glands have nothing to do with the thyroid gland — they simply sit behind it. You have four parathyroid glands, each roughly the size of a grain of rice, located on the back surface of the thyroid in your neck. Their sole function is to monitor blood calcium levels second by second and release PTH when calcium drops too low.
Think of them as the body's calcium thermostat — constantly sensing the temperature (calcium level) and turning the heat up (PTH release) whenever it drops. When calcium is normal or high, they stay quiet. When calcium falls, they secrete PTH within seconds. This makes PTH one of the most rapidly responsive hormones in the body.
पैराथायरॉइड ग्रंथियां थायरॉइड से अलग होती हैं — वे बस उसके पीछे स्थित होती हैं। आपके पास चार पैराथायरॉइड ग्रंथियां हैं, प्रत्येक चावल के एक दाने के आकार की। इनका एकमात्र काम रक्त में कैल्शियम की निगरानी करना और जरूरत पड़ने पर PTH स्रावित करना है। ये शरीर के कैल्शियम थर्मोस्टेट की तरह काम करती हैं।- Bone: Pulls calcium out of bones into the blood (activates osteoclasts — bone-dissolving cells)
- Kidney: Tells the kidneys to reabsorb calcium from urine instead of excreting it, AND activates Vitamin D to its usable form (calcitriol)
- Intestine: By activating Vitamin D, indirectly increases calcium absorption from food
Normal PTH Range in India / सामान्य सीमा
*PTH reference ranges vary significantly between laboratories and assay methods. The values below are for intact PTH (iPTH) — the standard modern assay. Always refer to the reference range on your specific lab report. Units may be pg/mL or pmol/L.
*PTH संदर्भ सीमाएँ लैब और परख विधि के आधार पर काफी भिन्न होती हैं। नीचे दिए मान Intact PTH (iPTH) के लिए हैं — आधुनिक मानक परख। अपनी रिपोर्ट की सीमा हमेशा देखें।| Category / वर्ग | PTH Level (pg/mL) | Interpretation / अर्थ |
|---|---|---|
| Normal सामान्य |
15 – 65 pg/mL | Parathyroid glands functioning normally. Calcium balance intact. |
| Low PTH कम PTH |
< 15 pg/mL | Parathyroid glands suppressed or damaged. Calcium may be high (glands turned off) or low (gland failure/hypoparathyroidism). |
| Mildly Elevated हल्का बढ़ा हुआ |
65 – 200 pg/mL | Usually secondary hyperparathyroidism — glands working harder to compensate for Vitamin D deficiency or kidney disease. |
| Significantly Elevated काफी बढ़ा हुआ |
> 200 pg/mL | Strongly suggests primary hyperparathyroidism (gland tumour) or severe secondary HPT in kidney failure. Urgent evaluation needed. |
The Master Table: PTH + Calcium Patterns / PTH और कैल्शियम का संयुक्त अर्थ
This is the most clinically important section of this guide. Doctors use the combination of PTH and calcium — not either value alone — to pinpoint the exact diagnosis. Here are all the key patterns:
यह इस गाइड का सबसे महत्वपूर्ण खंड है। डॉक्टर PTH और कैल्शियम के संयोजन का उपयोग करते हैं — किसी एक मान का नहीं — सटीक निदान के लिए।
| Calcium / कैल्शियम | PTH | Diagnosis / निदान | Most Common Cause in India |
|---|---|---|---|
| Normal | Normal | Normal calcium regulation | Healthy parathyroid function |
| Low | High ↑↑ | Secondary Hyperparathyroidism द्वितीयक हाइपरपैराथायरॉइडिज्म |
Vitamin D deficiency (most common in India), Chronic Kidney Disease — glands compensating correctly |
| High ↑↑ | High ↑↑ | Primary Hyperparathyroidism प्राथमिक हाइपरपैराथायरॉइडिज्म |
Parathyroid adenoma (benign tumour) — glands misbehaving, releasing PTH when they should not |
| High ↑↑ | Low / Suppressed | Non-PTH-mediated Hypercalcaemia PTH-स्वतंत्र अधिक कैल्शियम |
Malignancy (cancer releasing PTHrP), Vitamin D toxicity, sarcoidosis — glands correctly suppressed but calcium still high |
| Low | Low / Normal | Hypoparathyroidism हाइपोपैराथायरॉइडिज्म |
Post-thyroid surgery (most common), autoimmune, rare genetic — glands damaged or absent |
| Normal | High ↑↑ | Normocalcaemic Hyperparathyroidism नॉर्मोकैल्सेमिक हाइपरपैराथायरॉइडिज्म |
Early primary HPT or Vitamin D deficiency masking high calcium. Needs further investigation with Vitamin D and 24-hr urine calcium. |
High PTH (Hyperparathyroidism) — Types & Causes / उच्च PTH
Elevated PTH is called Hyperparathyroidism. There are three distinct types — and the type determines the treatment completely differently:
बढ़े हुए PTH को हाइपरपैराथायरॉइडिज्म कहते हैं। तीन अलग-अलग प्रकार हैं — और प्रकार उपचार को पूरी तरह निर्धारित करता है।Pattern: Low calcium + High PTH
Cause: The glands are normal but working overtime to compensate for something else — most commonly Vitamin D deficiency (India's #1 cause) or Chronic Kidney Disease. The elevated PTH here is a correct response, not a gland problem. Treat the root cause (Vitamin D / kidney disease) and PTH normalises. No surgery needed.
Pattern: High calcium + High PTH
Cause: One or more parathyroid glands develop a benign tumour (adenoma) and autonomously produce excess PTH regardless of calcium levels — a gland malfunction. Most common in post-menopausal women over 50. Often discovered incidentally on routine blood tests. Many patients are asymptomatic for years. Treatment is surgical removal of the adenoma (parathyroidectomy).
Pattern: High calcium + Very High PTH in a kidney patient
Cause: Occurs in long-standing kidney failure where the parathyroid glands have been overstimulated for so long that they develop autonomous function — continuing to produce excess PTH even after kidney transplant or correction of Vitamin D deficiency. Treated surgically.
Classic: "Bones, Stones, Groans, Psychic Moans" — bone pain and osteoporosis, kidney stones, abdominal pain, constipation, nausea, fatigue, depression, difficulty concentrating. Many patients with primary HPT in India are asymptomatic — found only through abnormal calcium on routine tests.
Low PTH (Hypoparathyroidism) — Causes & Symptoms / कम PTH
When PTH is too low — or absent — the body loses its ability to raise blood calcium. The result is persistently low calcium (hypocalcaemia) with all its consequences: muscle cramps, tetany, tingling, and in severe cases, seizures and cardiac arrhythmias.
जब PTH बहुत कम या अनुपस्थित होता है, तो शरीर रक्त कैल्शियम बढ़ाने की क्षमता खो देता है। इसका परिणाम है लगातार कम कैल्शियम: मांसपेशी ऐंठन, टेटनी, झुनझुनी और गंभीर मामलों में दौरे।The most common cause in India — accidental removal or damage of the parathyroid glands during thyroid surgery, neck dissection for cancer, or parathyroid surgery itself. Can cause acute severe hypocalcaemia within 24–48 hours of surgery (tingling, muscle cramps, Chvostek's sign, Trousseau's sign). May be temporary or permanent.
The immune system attacks and destroys the parathyroid glands. May occur alone or as part of autoimmune polyendocrine syndrome (APS). Often associated with other autoimmune conditions — check for thyroid antibodies, adrenal antibodies, and candida infections.
Low magnesium impairs PTH secretion AND makes tissues resistant to PTH action. A critical and commonly missed cause — the calcium and PTH will not normalise until magnesium is corrected first. Check serum electrolytes for magnesium levels in unexplained hypoparathyroidism or hypocalcaemia.
Rare — DiGeorge syndrome (22q11 deletion) causes absent or underdeveloped parathyroid glands from birth, presenting as neonatal hypocalcaemia and seizures. Other rare genetic forms include AIRE gene mutations and activating mutations of the calcium-sensing receptor (CaSR).
What to Do If Your PTH Is Abnormal / असामान्य PTH आने पर क्या करें?
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Never interpret PTH alone — always with calcium and Vitamin D
A single PTH result without corresponding calcium and Vitamin D levels is uninterpretable. If your doctor ordered PTH and you do not have a concurrent calcium and Vitamin D result, ask for them before any further management. The cause — and therefore the treatment — is entirely different depending on the combination.
PTH अकेले अर्थहीन है। इसे हमेशा कैल्शियम और विटामिन D के साथ मिलाकर देखें। यदि आपके पास एक साथ सभी तीन परिणाम नहीं हैं, तो आगे की कार्रवाई से पहले ये जांचें। -
If Low Calcium + High PTH: treat Vitamin D deficiency first
In India, this is by far the most common pattern and almost always means Vitamin D deficiency driving secondary hyperparathyroidism. Vitamin D3 supplementation (as directed by your doctor — typically 60,000 IU weekly for 8–12 weeks, then maintenance) will normalise calcium and bring PTH down. No surgery, no calcium infusions needed in most cases. Always confirm with a Vitamin D level before starting supplements.
भारत में यह सबसे आम पैटर्न है — विटामिन D की कमी द्वितीयक हाइपरपैराथायरॉइडिज्म पैदा करती है। विटामिन D3 सप्लीमेंट (डॉक्टर के निर्देशानुसार) कैल्शियम को सामान्य करेगा और PTH को कम करेगा। -
If High Calcium + High PTH: see an Endocrinologist — possible parathyroid adenoma
This pattern means primary hyperparathyroidism — a parathyroid gland tumour. Your doctor will order a sestamibi parathyroid scan or neck ultrasound to locate the overactive gland. A 24-hour urine calcium test distinguishes primary HPT from familial hypocalciuric hypercalcaemia (FHH) — a benign genetic condition that mimics primary HPT but does not need surgery. Surgical cure rate for parathyroid adenoma is over 95%.
यह पैटर्न प्राथमिक हाइपरपैराथायरॉइडिज्म का संकेत है — संभावित पैराथायरॉइड एडेनोमा। एंडोक्राइनोलॉजिस्ट से मिलें। सेस्टामिबी स्कैन या नेक अल्ट्रासाउंड ग्रंथि का पता लगाएगा। सर्जरी की सफलता दर 95% से अधिक है। -
If High Calcium + Low PTH: urgent cancer investigation
When calcium is high but PTH is suppressed (low), the parathyroid glands are responding correctly — they have switched off. But something else is raising calcium. The most dangerous cause is malignancy — cancer producing PTHrP (PTH-related protein) or spreading to bone. A chest X-ray, serum protein electrophoresis (SPEP for myeloma), PSA (in men), and CT scan may be needed urgently. Do not delay this evaluation.
जब कैल्शियम उच्च हो लेकिन PTH दबा हुआ (कम) हो — सबसे खतरनाक कारण कैंसर है। तत्काल जांच: छाती X-ray, SPEP (मायलोमा), PSA (पुरुषों में), CT स्कैन। इस मूल्यांकन में देरी न करें। -
If Low Calcium + Low PTH: Hypoparathyroidism — long-term calcium and active Vitamin D needed
This is hypoparathyroidism — the glands are absent, damaged, or not functioning. Management requires lifelong calcium and active Vitamin D (calcitriol or alfacalcidol — not regular cholecalciferol/D3, which requires kidney activation that PTH normally drives). These patients need regular serum calcium monitoring to avoid both under- and over-treatment. Check magnesium first — hypomagnesaemia must be corrected as it prevents PTH secretion.
यह हाइपोपैराथायरॉइडिज्म है — ग्रंथियां अनुपस्थित या क्षतिग्रस्त हैं। आजीवन कैल्शियम और सक्रिय विटामिन D (कैल्सिट्रियल) की आवश्यकता है — नियमित D3 नहीं, जिसे PTH द्वारा संचालित किडनी सक्रियण की आवश्यकता होती है।
Test Preparation / टेस्ट की तैयारी
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Morning sample — mandatory — PTH has a significant diurnal (daily) variation. It peaks in the early morning hours (around 2–4 AM) and is lowest in the afternoon. For reproducible, standardised results, blood must be collected between 8–10 AM in the fasting state. An afternoon PTH result can be 30–50% lower than a morning value in the same patient — making morning collection non-negotiable. PTH में महत्वपूर्ण दैनिक उतार-चढ़ाव होता है — सुबह 2–4 बजे सबसे अधिक और दोपहर में सबसे कम। दोपहर का PTH सुबह के मान से 30–50% कम हो सकता है। सुबह 8–10 बजे का सैंपल अनिवार्य है।
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Fasting 8–12 hours required — PTH is affected by recent food intake, particularly calcium-containing foods. A fasting sample eliminates this variable and also allows simultaneous fasting glucose, lipids, and kidney function to be drawn from the same sample. 8–12 घंटे का उपवास आवश्यक है — हाल के कैल्शियम युक्त खाद्य पदार्थ PTH को प्रभावित करते हैं। केवल सादा पानी पीएं।
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Sample must be kept cold and processed immediately — PTH degrades rapidly at room temperature. The blood sample must be placed on ice immediately after collection and centrifuged within 30–60 minutes. If the sample sits at room temperature, PTH values fall significantly — giving a falsely low result. Always use a NABL-accredited lab with good cold-chain sample handling. PTH कमरे के तापमान पर तेजी से टूट जाता है। सैंपल को तुरंत बर्फ पर रखना और 30–60 मिनट में सेंट्रीफ्यूज करना जरूरी है। गलत (कम) परिणाम से बचने के लिए NABL लैब चुनें।
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Stop Vitamin D and calcium supplements 48–72 hours before — Vitamin D and calcium supplements directly affect calcium levels, which in turn suppress or stimulate PTH. Stopping them 48–72 hours before the test gives a true baseline reading. Do not stop any prescribed medicines without your doctor's specific advice. विटामिन D और कैल्शियम सप्लीमेंट 48–72 घंटे पहले बंद करें — ये कैल्शियम को प्रभावित करते हैं जो PTH को दबाता या उत्तेजित करता है। डॉक्टर की सलाह के बिना कोई अन्य दवा बंद न करें।
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Always test calcium, Vitamin D, and magnesium alongside PTH — PTH without concurrent calcium is uninterpretable. Vitamin D and magnesium (serum electrolytes) are essential context. Most endocrinologists order all four together: PTH + Calcium + Vitamin D + Magnesium. If your doctor has ordered only PTH, ask whether the others should be added to the same blood draw. PTH के साथ हमेशा कैल्शियम, विटामिन D और मैग्नीशियम एक साथ जांचें। इनके बिना PTH का अर्थ नहीं निकाला जा सकता। अधिकांश एंडोक्राइनोलॉजिस्ट एक ही बार में चारों जांचते हैं।
Related Tests / संबंधित जांचें
PTH is never ordered alone — these tests are always needed alongside or immediately after for complete interpretation:
PTH कभी अकेले नहीं करवाया जाता — पूर्ण व्याख्या के लिए ये जांचें हमेशा साथ या तुरंत बाद जरूरी हैं:Frequently Asked Questions / अक्सर पूछे जाने वाले सवाल
The normal range for Intact PTH (iPTH) — the standard modern assay — is 15–65 pg/mL in most Indian laboratories. However, reference ranges vary significantly between labs and assay methods. Always refer to the range printed on your specific report. PTH must always be interpreted alongside a simultaneously drawn serum calcium — the combination is what gives the clinical meaning.
उत्तर: Intact PTH (iPTH) की सामान्य सीमा अधिकांश भारतीय लैब में 15–65 pg/mL है। लेकिन यह लैब और परख विधि के अनुसार काफी भिन्न होती है। अपनी रिपोर्ट की सीमा देखें। PTH हमेशा एक साथ लिए गए कैल्शियम के साथ व्याख्या करें।This is called Normocalcaemic Hyperparathyroidism — elevated PTH with normal calcium. It has two main explanations. First, it may be early primary hyperparathyroidism where the adenoma is producing excess PTH but the body is still maintaining normal calcium. Second — and far more common in India — it represents secondary hyperparathyroidism from Vitamin D deficiency where the glands are working harder but still keeping calcium in the normal range. Your doctor will order Vitamin D, a 24-hour urine calcium, and possibly a repeat test after correcting any Vitamin D deficiency to distinguish these.
उत्तर: इसे "नॉर्मोकैल्सेमिक हाइपरपैराथायरॉइडिज्म" कहते हैं। भारत में सबसे आम कारण है विटामिन D की कमी — ग्रंथियां कड़ी मेहनत कर रही हैं लेकिन कैल्शियम अभी सामान्य है। विटामिन D ठीक करने के बाद दोबारा जांचें।Primary: The gland itself has a problem (usually a benign adenoma) — it produces excess PTH autonomously regardless of calcium levels. Calcium is high. Treated by surgery.
Secondary: The glands are normal but responding correctly to low calcium — working overtime because something else (Vitamin D deficiency, kidney disease) is pulling calcium down. This is the correct and expected response. PTH is high but calcium is low. Treated by fixing the underlying cause.
Tertiary: Occurs after prolonged secondary hyperparathyroidism (usually in kidney failure) — the glands have been stimulated for so long they develop autonomous function and keep producing PTH even when calcium is corrected. Treated by surgery.
Yes — and more specifically, it requires a morning fasting sample. PTH has a significant diurnal rhythm and can fall 30–50% in the afternoon. The sample must also be kept cold and processed within 60 minutes of collection, as PTH degrades rapidly at room temperature. Stop Vitamin D and calcium supplements 48–72 hours before the test, and always draw calcium, Vitamin D, and magnesium at the same time.
उत्तर: हाँ — और विशेष रूप से सुबह का उपवास सैंपल जरूरी है। PTH दोपहर में 30–50% कम हो सकता है। सैंपल को ठंडा रखना और 60 मिनट में प्रोसेस करना अनिवार्य है। 48–72 घंटे पहले विटामिन D और कैल्शियम सप्लीमेंट बंद करें।Yes — Chronic Kidney Disease (CKD) is a major cause of secondary hyperparathyroidism and is the most common cause of very high PTH (above 300–500 pg/mL) in India. The kidneys fail in two ways: they can no longer activate Vitamin D to its usable form (calcitriol), causing calcium absorption to fall; and they cannot properly excrete phosphate, which independently stimulates PTH. The result is a powerful and sustained drive to PTH secretion. In advanced CKD, PTH can rise to 10–20 times the normal range. This is why a Kidney Function Test (KFT) is mandatory whenever PTH is significantly elevated.
उत्तर: हाँ — CKD भारत में 300–500 pg/mL से अधिक PTH का सबसे आम कारण है। किडनी विटामिन D सक्रिय नहीं कर पाती और फास्फेट नहीं निकाल पाती — दोनों PTH को बहुत उत्तेजित करते हैं। उच्च PTH होने पर KFT अनिवार्य है।No — the vast majority (over 85%) of parathyroid tumours causing primary hyperparathyroidism are benign adenomas — single gland overgrowths that are cured by surgical removal. Multiple gland enlargement (hyperplasia) accounts for most of the rest and is also benign. Parathyroid carcinoma (cancer) is extremely rare — accounting for less than 1% of primary hyperparathyroidism cases. It is suspected when PTH is extremely high (above 500 pg/mL), calcium is very high (above 14 mg/dL), and a firm neck mass is palpable. A straightforward parathyroid adenoma has a surgical cure rate above 95% and does not recur.
उत्तर: नहीं — 85% से अधिक पैराथायरॉइड ट्यूमर सौम्य एडेनोमा हैं जो सर्जरी से ठीक हो जाते हैं। पैराथायरॉइड कैंसर अत्यंत दुर्लभ है — 1% से कम। एडेनोमा की सर्जिकल सफलता दर 95% से अधिक है और यह दोबारा नहीं होता।- MedlinePlus (NIH): Parathyroid Hormone (PTH) Test — Patient Information
- American Association of Endocrine Surgeons (AAES): AAES Guidelines for Management of Primary Hyperparathyroidism — JAMA Surgery
- NCBI / StatPearls: Hyperparathyroidism — Medical Reference
⚠️ Medical Disclaimer / चिकित्सा अस्वीकरण
This article is for educational purposes only and does not constitute medical advice. PTH results must always be interpreted by a qualified doctor — preferably an Endocrinologist — in the context of simultaneously measured calcium, Vitamin D, kidney function, and clinical symptoms. Do not start or stop any treatment based on this guide alone.
यह लेख केवल शैक्षिक उद्देश्यों के लिए है। PTH परिणाम हमेशा एक योग्य डॉक्टर — अधिमानतः एंडोक्राइनोलॉजिस्ट — द्वारा एक साथ मापे गए कैल्शियम, विटामिन D, किडनी फंक्शन और नैदानिक लक्षणों के संदर्भ में समझे जाने चाहिए।
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