Parathyroid Hormone PTH Blood Test

What is a PTH blood test, and why is it important?

A PTH blood test measures the levels of parathyroid hormone in the blood. This test is important because it helps diagnose and monitor conditions related to calcium and phosphorus metabolism, such as hyperparathyroidism or hypoparathyroidism, and can guide treatment decisions for these conditions.

Parathyroid Hormone PTH Blood Test

The PTH test is used to help identify hyperparathyroidism, to find the cause of abnormal calcium levels, or to check the status of chronic kidney disease. PTH controls calcium and phosphorus levels in the blood.

A parathyroid hormone (PTH) blood test measures the level of parathyroid hormone in the blood. This test is used to help identify hyperparathyroidism, to find the cause of abnormal calcium levels, or to check the status of chronic kidney disease. PTH controls calcium and phosphorus levels in the blood. The four pea-sized parathyroid glands that are located behind the thyroid gland produce PTH. If the blood calcium level is too low, the parathyroid glands release more PTH. As a result, the amount of calcium that the kidneys release into the urine decreases, and the bones release more calcium into the blood. Also, vitamin D is converted to a more active form, causing the intestines to absorb more calcium and phosphorus, which can decrease high PTH. Some symptoms and medical conditions may cause your doctor to measure how much PTH is in your blood. Because the amount of PTH in your blood changes with the amount of calcium in your blood, your health care provider will usually order a calcium blood test along with a PTH test. Comparing the results of both tests helps your provider understand if your parathyroid glands are working properly to control your calcium levels. PTH levels that are too high or too low can cause problems with the kidneys and bones and cause changes in calcium and vitamin D levels.

This hormone shouldn't be confused with the thyroid hormones because they serve different roles in the body.

What Is the Parathyroid Hormone?

The PTH blood test measures the level of parathyroid hormone in the blood, a protein hormone released by the parathyroid glands[2]. The parathyroid glands are four small glands located in the neck, near or attached to the backside of the thyroid gland[3]. These glands play a significant role in controlling calcium, phosphorus, and vitamin D levels in the blood[1].

The parathyroid hormone (PTH) is also known as parathyrin. It's responsible for influencing the calcium levels in the blood. For example, if the calcium levels drop, it can make the bones release more calcium into the bloodstream. At the same time, it can also facilitate the absorption of calcium into the bones and teeth when necessary.

What Are the Roles of PTH?

PTH serves several functions in the human body, mainly related to the absorption and release of calcium and phosphate. For example, let's take a look at how PTH affects the bones in your body.

What is a PTH Blood Test?

A PTH blood test is done to measure the levels of parathyroid hormone in the blood. To do that, doctors need a single blood sample drawn from the arm of a patient. You can order your PTH test online and obtain the results of the test in a few business days. During the test, a health care professional will take a blood sample from a vein in your arm using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Depending on the results, your doctor might ask for more investigation or not. For example, if you have hypocalcemia, your doctor might consider supplementation with calcium. If your body also secretes low levels of PTH, the doctor might ask for a thorough investigation of your thyroid.

Make sure you stop supplementation with biotin (vitamin B7) for 72 hours before the test since this can alter the results.

How Does PTH Work?

1. The Rapid Absorption Phase

Once the parathyroid glands release a great quantity of PTH, the bone cells absorb calcium and phosphate in the bloodstream. The process starts within seconds from the moment of the secretion of PTH. The bone cells (called osteocytes) fixate the calcium in the bones, making them stronger and less predisposed to fractures.

2. The Slow Release Phase

This phase consists of the release of calcium and phosphate into the bloodstream. PTH influences the bone cells to gradually break down the bone to release these minerals when necessary. The process takes days and even weeks, and it usually occurs when the calcium levels in the blood drop to dangerous levels.

3. Effect on Kidneys

It is estimated that around 10% of all the calcium you get from food is lost through urine. When the blood calcium levels drop, the parathyroid glands release a lot of PTH to make the kidneys reabsorb some of the calcium in the urine. At the same time, PTH can also improve the release of phosphate in the urine, eliminating it from the body at a greater rate.

4. Improving Calcium Absorption in the Gut

Calcium gets absorbed better in the presence of vitamin D. When the calcium levels are low, the PTH transforms some 25-hydroxycholecalciferol into 1.25-dihydroxycholecalciferol. This hormone is a better version of vitamin D and will absorb more calcium in the stomach and intestines.

Uses of the PTH Blood Test

1. Monitoring Calcium Levels: The primary function of the PTH blood test is to determine the amount of parathyroid hormone present, as it directly affects calcium levels in the blood[4]. By measuring PTH, healthcare providers can assess if there is an imbalance in the body's calcium regulation.
2. Identifying Hypercalcemia or Hypocalcemia: The PTH blood test is often ordered when other tests indicate high or low levels of calcium in the blood[5]. It is also commonly ordered when someone presents with signs and symptoms of hypercalcemia (high calcium) or hypocalcemia (low calcium). Symptoms of hypercalcemia may include abdominal pain, fatigue, increased thirst, and nausea[5].

Is There a Difference Between a PTH Intact Blood Test and a Regular PTH Blood Test?

Yes, there is a difference between a PTH Intact Blood Test and a regular PTH Blood Test. The PTH Intact Blood Test measures the level of intact parathyroid hormone in the blood, which is the biologically active form of the hormone. On the other hand, a regular PTH blood test measures both intact and fragmented forms of parathyroid hormone in the blood. The PTH Intact Blood Test is more accurate for diagnosing certain conditions, such as hyperparathyroidism, while a regular PTH Blood Test may be used for general screening purposes. It is important to consult with your healthcare provider to determine which test is appropriate for your specific needs.

What are the Normal Levels of PTH in the Blood?

People who have normal levels of circulating PTH also enjoy stable calcium and phosphorus balance. They don't have kidney issues or problems with their bones. Here are the normal ranges of PTH in the body:

• 50-330 ng/L for C-terminal and mid-molecule in adults
• 51-217 ng/L for kids

Doctors measure other aspects related to the parathyroid hormone. For example, the ranges of PTH as an intact molecule are:

• 0-65 ng/L for adults
• 9-52 ng/L for kids

Anything that goes lower or higher than these reference values might be classified as hypoparathyroidism or hyperparathyroidism. A simple blood test will reveal if the parathyroid glands are functioning properly.

What are the Symptoms of Low PTH?

Certain symptoms will appear when the levels of PTH in your body get too low. For example:

• Dry skin and dry hair
• Headaches and memory problems
• Cataracts and other eye conditions
• Muscle spasms
• Seizures
• Abnormal heart rhythm
• Poorly functioning kidneys
• Teeth problems

It's important to note that these symptoms might be severe or mild for different people. That's why a PTH test is required to determine if the parathyroid glands are working fine. When the PTH levels get too low, your calcium levels will drop while the phosphorus ones will increase.

Various factors, such as an injury to the parathyroid glands due to surgery, might cause low secretion of PTH. At the same time, some patients might have PTH in their blood, but an autoimmune disease prevents the patient's body from processing these hormones correctly.

What are the Symptoms of High PTH?

It's also possible to have high PTH levels in your blood. This is called hyperparathyroidism, and it can be split into two categories. It might be a result of enlarged parathyroid glands that abnormally secrete too much PTH. This can usually be fixed through surgery as the doctor removes the inflamed parathyroid gland.

Very low calcium levels in the body can also cause hyperparathyroidism. For example, if a different disease causes low calcium, the parathyroid gland might secrete too much PTH in an attempt to re-establish calcium balance in the body. The symptoms of hyperparathyroidism include:

•  Abdominal pain
•  Frequent and excessive urination
•  Vomiting and nausea
•  Bone pain
•  Anxiety and depression
•  Kidney problems
•  Persistent weakness that doesn't go away after a good night's sleep

Get the PTH Blood Test Today!

As you can see, the parathyroid glands are pulling the strings in the background to maintain stable calcium and phosphorus values in your body. If you want to enjoy having strong bones and vibrant health in general, you should do the PTH test as soon as possible. This test will reveal how healthy your parathyroid glands are and how much PTH is circulating in your body.

If you're looking for an affordable and convenient option to get a PTH blood test, DiscountedLabs.com is an excellent choice. They offer a wide range of lab tests, including the PTH blood test, at significantly discounted prices. Their simple and user-friendly website makes it easy to order the tests you need, and they have a network of partner labs across the United States, making it convenient to find a lab near you.

References:

[1] "Parathyroid hormone (PTH) blood test Definition The PTH test measures the level of parathyroid hormone in the blood. PTH stands for parathyroid hormone. It is a protein hormone that the parathyroid gland releases. A laboratory test can be done to measure the amount of PTH in your blood. Alternative Names" URL: https://www.ucsfhealth.org/medical-tests/parathyroid-hormone-(pth)-blood-test https://my.clevelandclinic.org/health/articles/22355-parathyroid-hormone

[2] "Why the Test is Performed. PTH is released by the parathyroid glands. The 4 small parathyroid glands are located in the neck, near or attached to the back side of the thyroid gland. The thyroid gland is located in the neck, just above where your collarbones meet in the middle. PTH controls calcium, phosphorus, and vitamin D levels in the blood." URL: https://ufhealth.org/parathyroid-hormone-pth-blood-test

[3] "The PTH blood test is used to determine the amount of parathyroid hormone that is present. The parathyroid gland releases PTH, a protein hormone. There are actually 4 tiny glands located in the neck, attached to or near the thyroid gland, and this protein hormone controls calcium levels in the blood." URL: https://healthresearchfunding.org/pth-blood-test-results-explained/