Quick Facts
- Sample: Venous blood draw
- Fasting: Not required (morning sample preferred)
- Turn-around: 5-8 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Know your hormone status — Measure intact PTH to understand calcium and bone health.
- Convenient monitoring — Track parathyroid function without scheduling clinic visits.
- Actionable insights — Results guide vitamin D therapy, imaging, or surgical decisions.
- Cost-effective bundling — Pair with calcium, phosphorus, and vitamin D for comprehensive mineral assessment.
- Timely answers — Get secure online results within days to share with your doctor.
Who Is This Test For?
- People with high calcium, kidney stones, or unexplained bone loss.
- Adults managing chronic kidney disease (CKD stages 3–5) with mineral-bone disorder.
- Anyone recovering from thyroid or parathyroid surgery experiencing tingling or cramps.
- Individuals with fatigue, muscle spasms, or bone pain linked to calcium imbalance.
- Those monitoring diagnosed hyperparathyroidism or hypoparathyroidism under physician guidance.
How It Works – Just 3 Steps
- Order online — Receive your lab requisition and locate a nearby draw center.
- Visit the lab — A quick venous blood draw; no shipping needed.
- Get results — Access secure results online within 5-8 business day.
FAQ
What does this test measure? This test measures intact parathyroid hormone (PTH) levels, which regulate calcium, phosphorus, and bone metabolism in your body.
Do I need to fast before the test? Fasting is not required, though morning samples are preferred due to PTH's diurnal variation.
Can medications affect my results? Yes—high-dose biotin, lithium, vitamin D analogs, and calcimimetics may influence PTH or calcium levels; discuss any supplements or medications with your doctor before testing.
How often should I retest? Frequency depends on your condition: every 6–12 months for stable hyperparathyroidism or CKD, more often after therapy changes.
What if my PTH is abnormal? Abnormal results should be discussed with your primary care doctor, endocrinologist, or nephrologist, who may order imaging, adjust medications, or consider surgery.
Is this test useful if I have kidney disease? Yes—guidelines recommend periodic PTH testing in CKD stages 3–5 to monitor secondary hyperparathyroidism and adjust treatment (KDIGO CKD-MBD Guidelines 2017).
More Details
What is the purpose of this test?
The intact parathyroid hormone (PTH) blood test measures PTH levels to assess how well your parathyroid glands regulate calcium and phosphorus balance. PTH is produced by four small glands in your neck and plays a critical role in bone metabolism, kidney function, and vitamin D activation. Measuring intact PTH—the biologically active form—helps diagnose primary hyperparathyroidism (overactive glands causing high calcium), secondary hyperparathyroidism (often from vitamin D deficiency or chronic kidney disease), and hypoparathyroidism (underactive glands causing low calcium). Results guide treatment decisions including imaging, surgery, vitamin D supplementation, and medications (Endocrine Society 2022).
Who would benefit from this test?
You may benefit from PTH testing if you have high or borderline-high blood calcium, recurrent kidney stones, unexplained bone loss or fractures, chronic kidney disease, or symptoms of low calcium such as tingling, muscle cramps, or spasms. This test is also valuable for individuals with a family history of parathyroid disorders, prior neck surgery involving the thyroid or parathyroid glands, or diagnosed osteoporosis. People managing CKD stages 3–5 should monitor PTH regularly, as elevated levels are linked to bone disease, vascular calcification, and higher mortality (KDIGO CKD-MBD Quick Reference 2022).
When should I order this test?
Order PTH testing when blood calcium is abnormal, when you have symptoms of calcium imbalance (bone pain, fatigue, kidney stones, muscle spasms), or when chronic kidney disease is present with suspected mineral-bone disorder. PTH testing is also appropriate after thyroid or parathyroid surgery to check for hypoparathyroidism, or periodically if you have diagnosed hyperparathyroidism or hypoparathyroidism to monitor trends. Proactive users managing kidney disease or osteoporosis risk may order PTH every 6–12 months under physician guidance to track disease progression and treatment response (AAES Guidelines 2016).
How do I interpret the results?
PTH results must be interpreted alongside serum calcium, kidney function, and vitamin D levels. Abnormal results outside your lab's reference range should be confirmed with repeat testing. Always discuss results with a healthcare professional before making treatment decisions.
High PTH + High calcium
- Meaning: Likely primary hyperparathyroidism
- Typical action: Imaging (ultrasound, sestamibi scan); possible surgery
High PTH + Normal/low calcium
- Meaning: Secondary hyperparathyroidism (e.g., vitamin D deficiency, CKD)
- Typical action: Vitamin D supplementation; phosphate binders; treat underlying CKD
Low PTH + Low calcium
- Meaning: Hypoparathyroidism
- Typical action: Calcium and vitamin D replacement; monitor symptoms
Normal PTH + Normal calcium
- Meaning: Appropriate parathyroid function
- Typical action: No immediate action; periodic monitoring if risk factors present
Primary hyperparathyroidism affects roughly 0.2–1% of U.S. adults, with higher prevalence in older women (Endocrine Society 2022).
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
Most intact PTH tests do not require fasting, but some clinicians prefer morning, fasting samples because PTH levels can vary throughout the day. Follow your lab's and your doctor's instructions. Certain medications—including high-dose biotin supplements (over 5,000 mcg daily), lithium, vitamin D analogs, and calcimimetics—can influence PTH or calcium results. Do not stop prescribed medications without consulting your healthcare provider. Recent calcium or vitamin D intake may also affect results, so discuss timing with your doctor before testing (PubMed 2022).
How often should I get tested?
Testing frequency depends on your condition, treatment status, and symptoms. Work with your healthcare provider to determine the right schedule for your situation.
- Stable primary hyperparathyroidism (no surgery): Every 6–12 months
- CKD stage 3: Every 6–12 months
- CKD stages 4–5: Every 3–6 months
- After starting vitamin D or calcimimetic therapy: 1–3 months initially, then every 3–6 months
- Postsurgical hypoparathyroidism: Every 3–6 months or as symptoms dictate
- Initial evaluation of suspected disorder: Repeat in 1–3 months to confirm abnormal result
Why early detection matters
Untreated parathyroid disorders lead to serious complications. Primary hyperparathyroidism increases fracture risk, kidney stone formation, and cardiovascular disease. In CKD, elevated PTH contributes to renal osteodystrophy (bone disease), vascular calcification, and increased mortality; patients with secondary hyperparathyroidism face healthcare costs 29–100% higher than CKD patients with normal PTH (PMC 2023). Hypoparathyroidism causes chronic hypocalcemia leading to tetany, seizures, heart rhythm abnormalities, and medical costs up to three times higher than matched controls (PubMed 2025). Early PTH testing enables timely vitamin D supplementation, medication adjustment, or surgery before irreversible complications occur.
Related tests you may consider
Comprehensive Metabolic Panel (CMP-14) with eGFR Blood Test - Used to evaluate nutrient levels, liver, and kidney function.
Vitamin D 25-Hydroxy Blood Test - Checks if you have enough vitamin D, helping to ensure your bones stay healthy and reducing the risk of various health issues associated with vitamin D deficiency..
Phosphorus Serum Test - measures the blood's phosphorus (phosphate) levels to help screen for an imbalance.
