hyperparathyroidism
Meaning of hyperparathyroidism: Overactive parathyroid glands pulling calcium out of bone and into the blood, often found on a routine test before symptoms appear.
Definition of hyperparathyroidism
Hyperparathyroidism is a condition in which one or more of the four parathyroid glands produce too much parathyroid hormone. That hormone raises calcium in the blood by releasing it from bone, reclaiming more from urine and increasing absorption from food. Sustained overproduction weakens bone and can lead to kidney stones, although many cases are found on a blood test before anything is noticed.
What do the parathyroid glands do?
Four glands, each about the size of a grain of rice, sit behind the thyroid gland in the neck. Despite the position they have nothing to do with thyroid function. Their sole job is to keep calcium in the blood within a narrow range, because nerves, muscle and the heart depend on a steady level. When calcium dips, they release parathyroid hormone; when it rises, they fall silent. Hyperparathyroidism is a failure of that off switch.
What are the types?
| Type | Cause | Blood calcium |
|---|---|---|
| Primary | A growth in one gland, usually benign | High |
| Secondary | Glands respond to kidney disease or low vitamin D | Low or normal |
| Tertiary | Glands keep working after long-standing secondary | High |
The distinction matters because the treatments differ entirely. Primary disease is a problem in the gland itself. Secondary disease is the gland behaving correctly in response to a problem elsewhere, most often in the kidney.
What does too much calcium do?
The classic description groups the effects by site. Bone loses mineral and becomes fragile. Kidneys form stones and may be damaged by calcium deposits. The digestive system slows, producing constipation, nausea and stomach discomfort. Nerves and mood are affected, giving fatigue, poor concentration, low mood and, at high levels, confusion. Thirst and frequent urination are common, because calcium interferes with the ability to concentrate urine. Many people have milder disease found through a routine blood test, and in that setting bone density and kidney imaging are used to judge whether damage is already occurring.
Used in a sentence
Persistently raised calcium with an unsuppressed hormone level confirmed primary hyperparathyroidism.
Good to know
Primary hyperparathyroidism raises blood calcium while the secondary form is a normal response to low calcium from kidney disease or vitamin D deficiency, so the calcium level separates them.
Word origin
Where “hyperparathyroidism” comes from
Built from the Greek hyper-, meaning above or excessive, with para-, beside, and the thyroid gland the parathyroids sit behind.