What do the Parathyroid glands do?
The parathyroid glands are four small grain size glands that lie next to (para) the thyroid gland. The parathyroid glands are endocrine glands that produce a hormone called parathyroid hormone (PTH) that regulates your bodys calcium levels by regulating the amount of calcium absorbed by your gut, depositing or retrieving calcium stored in your skeleton and regulate amount of calcium absorbed or lost via the kidneys into the urine.
The activity of the parathyroid gland is under direct control of the calcium in the blood. The higher the calcium level the less PTH is released and any excess calcium is deposited in the bone or loss in the urine. In simple terms, the parathyroid is likened to the bank manager where any excess money is deposited into savings account (bone) or spent (lost in urine by kidneys). If money is tight the bank manager may release funds from your savings account to maintain status quo (Click 'Parathyroid Control system').
What does an overactive parathyroid gland mean?
Overactive parathyroid gland (hyperparathyroidism) occurs when too much PTH is released resulting in raised calcium levels (calcium level can be normal). This can be caused by excess growth of one or more of these four parathyroid glands (primary hyperparathyroidism) or a result of chronic kidney failure or lack of vitamin D (secondary hyperparathyroidism). The vast majority (80%) of primary hyperparathyroidism is caused by a single gland. Occasionally more than one parathyroid gland may be involved especially if there is a family history of primary hyperparathyroidism.
The majority of secondary hyperparathyroidism is caused by chronic renal (kidney) failure. Vitamin D is produced in the kidneys and without them results in low calcium levels. This and the rise in blood phosphate levels stimulate the parathyroid glands to go into overdrive in order to maintain the blood calcium levels by increasing absorption via the gut and releasing calcium from the bones, working over-time and withdrawing from your savings account.
`Bones, stones, abdominal groans and psychic moans' are the classical description of hyperparathyroidism. In fact less than 50% of patients will complain of these symptoms. Most patients when first presented complain of very little...... .or do they? Studies have shown that in detail questioning most patients are to a degree symptomatic. The modern day clinical manifestation of primary hyperparathyroidism include a number of rather insidious symptoms which many sufferers often put down to age, stress, diet, etc.
Can I get Underactive Parathyroid glands?
The cause of Underactive parathyroid glands is mainly due to surgical injury to the parathyroid glands during thyroid surgery. This can be transient or permanent (see thyroid). This can be treated by taking calcium and vitamin D pills. Other causes of Underactive parathyroid glands are generally rare genetic disorders.
How will having high calcium and PTH affect me?
For most people the raised calcium is not life threatening unless it rises to above 3mmol/l. Urgent treatment is usually required if this happens. Some doctors think having a slightly raised calcium and PTH never really harm anybody and may even prescribe medications to bring the calcium down in order to avoid surgical treatment.
This unfortunately is not true. Having high calcium all the time means will make your bones weak and bring on or worsen osteoporosis. Taking medicine to keep the calcium near normal may only slow down this process. The PTH has until recently been thought of as an innocuous hormone. Studies have clearly demonstrated that even slightly raised levels of PTH can affect your heart and muscles. People with untreated hyperparathyroidism are at higher risk of having heart attacks and muscle wasting. In addition to this you may find your quality of life may be somewhat curtailed by not having it treated.
What treatments are available to treat Hyperparathyroidism?
The only definitive treatment for this is surgery. Nowadays we use sestamibi and ultrasound scans to locate the majority of the abnormal parathyroid gland(s) before surgery. This allows us to tailor the surgery accordingly through a scar about the size of a penny (less than 2.5cm), minimally invasive parathyroid surgery. This is in contrast to the more traditional approach of a 8 to 10 cm scar. The risk of surgery to the recurrent laryngeal nerve is minimal and because the surgery is usually targeted directly to the abnormal gland without disturbing the other normal glands postoperative hypocalcaemia following parathyroid surgery has become extremely rare.
In patients with a family history of hyperparathyroidism or multi-glands involvement, three and a half or removal of all four parathyroid glands may be carried out. This is to prevent progression of the disease as recurrence is almost inevitable in these cases if parathyroid glands are left behind. In these patients life long calcium and vitamin D supplement is required.
What will happen after surgery?
In experienced hands surgery should achieve greater than 95% cure. You will be invited to a few follow-up visits in clinic to monitor the calcium levels. In a small number of people who may have multi-gland disease, the other parathyroid glands may become abnormal and the blood calcium may rise again necessitating further surgery.