I remember a patient, let’s call her Sarah. She came in feeling just… off. Tired all the time, a bit foggy, and these odd little muscle twitches she couldn’t quite pin down. After a good chat, we decided to run some routine blood tests. And that’s when a little something called parathyroid hormone (often shortened to PTH) popped up on our radar, helping us understand what was happening. It’s a vital little messenger in your body, especially when it comes to managing your calcium.
So, what is this parathyroid hormone? Well, it’s a hormone made by your parathyroid glands. These are tiny glands, usually four of them, kind of snuggled in behind your thyroid gland in your neck. Their main job? To be the boss of the calcium levels in your blood. Now, calcium isn’t just about strong bones, though that’s a big part of its job, of course. It’s absolutely crucial for your nerves to send messages properly, for your muscles to contract – including your heart – and for so many other things to run smoothly. PTH also has a say in your phosphorus (another mineral) and vitamin D levels. It’s a bit of a multitasker!
How Parathyroid Hormone Keeps Things Balanced
You might be wondering how PTH actually pulls off this calcium-balancing act. It’s quite clever, really.
When your body senses that the calcium levels in your blood are a bit low, your parathyroid glands get the signal to release PTH. This hormone then works in a few ways:
- Bones: PTH gently nudges your bones to release a small amount of their stored calcium into your bloodstream. Just enough to help bring things back into the normal range.
- Kidneys: It tells your kidneys, “Hold onto that calcium! Don’t let it all go out in the pee.” Very importantly, PTH also helps your kidneys activate vitamin D.
- Small Intestine: This active vitamin D then signals your small intestine to absorb more calcium from the food you eat.
Your body has a pretty smart feedback system to control PTH levels. Low blood calcium? More PTH is released. Blood calcium levels rise back to where they should be? The parathyroid glands ease off on PTH production. Simple, right? Well, most of the time. Sometimes, an issue with the parathyroid glands themselves can cause them to release too much or too little PTH, no matter what the feedback loop is saying.
When Parathyroid Hormone Levels Go Rogue
When this delicate balance of parathyroid hormone is off, it can lead to certain health conditions. The symptoms you might feel are often due to the calcium levels in your blood being too high or too low.
Too Much PTH: Hyperparathyroidism
If your glands are overactive and churn out too much PTH, we call this hyperparathyroidism. This usually results in:
- High blood calcium levels (hypercalcemia)
- Often, low levels of phosphorus in your blood (hypophosphatemia)
What causes this? It could be a small, non-cancerous growth on one of the glands (a parathyroid adenoma – this is the most common reason), much more rarely, parathyroid cancer, or sometimes chronic kidney disease can play a role.
If your calcium is high, you might experience:
- Feeling really wiped out and fatigued
- Persistent headaches
- Achy joints and bone pain
- Noticing you’re peeing more frequently and feeling thirsty a lot
Too Little PTH: Hypoparathyroidism
On the other hand, if there’s not enough PTH, it’s called hypoparathyroidism. This typically leads to:
- Low blood calcium levels (hypocalcemia)
- Often, high levels of phosphorus in your blood (hyperphosphatemia)
This condition is less common. About three out of four cases happen because of accidental damage to the parathyroid glands during neck or thyroid surgery. Certain genetic conditions or autoimmune disorders can also be culprits.
With low calcium, symptoms can include:
- A sense of brain fog or confusion
- Dry skin and brittle nails
- Those bothersome muscle cramps or twitches
- A tingling sensation in your lips, fingers, or feet
If any of these symptoms sound familiar, it’s always a good idea to have a chat with your doctor. We can help figure out what might be going on.
How We Check Your Parathyroid Hormone
So, if we suspect something might be up with your PTH, how do we check it?
It’s usually done with a straightforward blood test. The lab folks and doctors often call this test “PTH, intact.”
Now, “normal” can be a bit of a tricky word in medicine because reference ranges for lab tests can vary slightly from one lab to another. Generally, a typical range for a PTH blood test is about 15 to 65 picograms per milliliter (pg/mL). A picogram is incredibly tiny – one-trillionth of a gram! But please don’t get too hung up on the numbers themselves. We always look at your specific result in the context of you and what the reporting lab considers its normal range.
If you have a PTH level test, I, or your healthcare provider, will go over your results carefully. We’ll let you know if you need any further tests or what the next steps might be. We’ll discuss all options and what they mean for you.
Key Things to Remember About Parathyroid Hormone
Here’s a quick rundown of the important bits:
- Parathyroid hormone (PTH) is the main player in controlling your blood calcium levels.
- It’s produced by four tiny glands in your neck and works on your bones, kidneys, and gut.
- Too much PTH (hyperparathyroidism) can cause high blood calcium, leading to symptoms like fatigue, aches, and increased thirst.
- Too little PTH (hypoparathyroidism) results in low blood calcium, which might cause muscle cramps, tingling, or brain fog.
- A simple blood test can measure your PTH levels if there’s a concern.
It’s a complex little system, isn’t it? But when it’s all working as it should, you probably don’t even give it a second thought. If you’re ever worried about these kinds of symptoms, please know you’re not alone, and we’re here to help explore what’s going on.