Understanding Normal PTH Levels: What Your Parathyroid Hormone Levels Really Mean

If you’ve been told your parathyroid hormone (PTH) levels are abnormal—or you’re unsure what “normal PTH levels” really mean—you’re not alone. Parathyroid hormone levels can be confusing, especially when calcium levels appear normal. However, understanding the role of PTH in your body is critical to diagnosing and treating parathyroid disease.

At the Norman Parathyroid Center, we specialize in evaluating parathyroid hormone levels and identifying the subtle patterns that often go overlooked. In this article, we’ll explain what the normal range of PTH is, what causes PTH levels to become abnormal, and why you shouldn’t rely on a single lab value to determine your health.

What Are Parathyroid Hormone (PTH) Levels?

Parathyroid hormone (PTH) is a hormone made by the parathyroid glands—four small glands located behind the thyroid. The main job of PTH is to regulate calcium levels in the blood. It does this by:

• Pulling calcium from bones
• Increasing calcium absorption in the intestines
• Decreasing calcium excretion in the urine

Because of this relationship, PTH levels and calcium levels are closely linked. But here’s the catch: many people with parathyroid disease have normal calcium or normal PTH levels on paper. That’s why looking at your parathyroid hormone levels in context is essential.

What Is the Normal Range for PTH Levels?

Most labs report the normal PTH range as approximately 10–65 pg/mL, although this can vary slightly by laboratory. This range is often referred to as the “PTH normal range.” However, interpreting these numbers in isolation can be misleading.

Key Point: A “normal” PTH level does not mean you are healthy if your calcium is high.

For example, if your calcium is 10.3 mg/dL (which is above normal) and your PTH is 42 pg/mL (in the “normal range”), that is abnormal. In this scenario, PTH should be low or even undetectable. If it’s not, the parathyroid glands are not responding appropriately, and you may have primary hyperparathyroidism.

Why Normal PTH Levels Can Still Indicate Disease

This is the number one mistake in diagnosing parathyroid disease: assuming that PTH levels in the “normal” range rule it out.

In primary hyperparathyroidism, the most common parathyroid disorder, PTH can be in the normal or high range while calcium is elevated.

Let’s say your calcium has been hovering around 10.2–10.5 mg/dL and your PTH levels bounce between 45 and 80 pg/mL. That’s a pattern consistent with hyperparathyroidism—even if your doctor tells you your labs are “normal.”

How We Interpret PTH Levels at the Norman Parathyroid Center

We’ve reviewed tens of thousands of cases of parathyroid disease, and we know that interpreting parathyroid hormone levels requires more than just reading a lab report. Here's what we look for:

• PTH levels that are too high for the current calcium level
• Calcium levels that are high or upper-normal over time
• PTH that remains elevated despite vitamin D correction
• Trends across multiple labs—not just one test

This approach allows us to detect subtle forms of the disease that are often missed elsewhere.

What Else Affects PTH Levels?

If you’ve been told your PTH levels are elevated or low, other factors might be influencing the result. These include:

• Vitamin D deficiency: Low vitamin D can cause PTH levels to rise.
• Kidney function: Chronic kidney disease can raise PTH levels.
• Calcium supplements: These can temporarily alter both calcium and PTH.
• Biotin supplements: These can interfere with lab results.

Even dehydration or lab timing can shift parathyroid hormone levels slightly. That’s why we always review the full picture before making any diagnosis.

What Are the Symptoms of Abnormal Parathyroid Hormone Levels?

Symptoms of elevated parathyroid hormone levels—especially in the context of hyperparathyroidism—can include:

• Fatigue
• Brain fog or memory problems
• Osteoporosis or fractures
• Kidney stones
• Bone and joint pain
• High blood pressure
• Anxiety or depression
• Gastrointestinal issues

If your calcium and parathyroid hormone levels are not in sync, and you’re experiencing symptoms like these, don’t ignore it. Even if your labs fall into the “normal” ranges, that doesn’t mean your parathyroid glands are functioning properly.

What to Do If Your PTH Levels Are Abnormal

If your parathyroid hormone levels are high, low, or fluctuating, your next step should be to talk to a parathyroid expert—not just an endocrinologist, but a surgeon who specializes in parathyroid disease. That’s because:

• Surgery is the only cure for primary hyperparathyroidism.
• Medication cannot fix an overactive parathyroid gland.
• Imaging scans are often misleading and must be interpreted by experienced specialists.

The Norman Parathyroid Center performs more parathyroid operations than any other center in the world. If your calcium or PTH levels are concerning, we’re here to help you make sense of them—and fix the problem for good.

Final Thoughts: Trust the Patterns, Not the Single Number

Many patients are told their labs are “fine” even when they aren’t. The truth is, normal PTH levels can still point to disease when viewed in context. Abnormal PTH levels don’t always mean a problem if other factors are involved.

At the Norman Parathyroid Center, we look at everything: your history, your calcium, your parathyroid hormone levels over time, your symptoms, and your overall health. If something doesn’t add up, we’ll find out why—and what to do about it.

Additional Resources:

• Learn more about the Norman Parathyroid Center.
• Read more on the Parathyroid blog.
• Become our patient.
• Check out our sister surgeons at the Clayman Thyroid Center, and the Carling Adrenal Center. We are now united under one roof, operating at the Hospital for Endocrine Surgery.