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Your thyroid gland is one of the endocrine glands, which make
hormones to regulate physiological functions in your body. The
thyroid gland manufactures thyroid hormone, which regulates the
rate at which your body carries on its necessary functions. Other
endocrine glands are the pancreas, the pituitary, the adrenal
glands, the parathyroid glands, the testes, and the ovaries.
The thyroid gland is located in the middle of the lower neck,
below the larynx (voice box) and just above your clavicles (collarbones).
It is shaped like a "bow tie," having two halves (lobes):
a right lobe and a left lobe joined by an "isthmus".
You can't always feel a normal thyroid gland.
Diseases of the thyroid gland are very common, affecting millions
of Americans. The most common diseases are an over- or under-active
gland. These conditions are called hyperthyroidism (e.g., Grave's
disease) and hypothyroidism. Sometimes the thyroid gland can
become enlarged from over-activity (as in Grave's disease) or
from under-activity (as in hypothyroidism). An enlarged thyroid
gland is often called a "goiter." Sometimes an inflammation
of the thyroid gland (Hashimoto's disease) will cause enlargement
of the gland.
Patients may develop "lumps" or "masses" in
their thyroid glands. They may appear gradually or very rapidly.
Patients who had radiation therapy to the head or neck as children
for acne, adenoids, or other reasons are more prone to develop
thyroid malignancy. A doctor should evaluate all thyroid "lumps" (nodules).
The diagnosis of a thyroid abnormality in function or a thyroid
mass is made by taking a medical history and a physical examination.
Specifically, your doctor will examine your neck and ask you
to lift up your chin to make your thyroid gland more prominent.
You may be asked to swallow during the examination, which helps
to feel the thyroid and any mass in it. Other tests your doctor
may order include:
1. An ultrasound examination of your neck and thyroid
2. Blood tests of thyroid function
3. A radioactive thyroid scan
4. A fine needle aspiration biopsy
5. A chest X-ray
6. A CT or MRI scan
If a lump in your thyroid is diagnosed, your doctor may recommend
a fine needle aspiration biopsy. This is a safe, relatively painless
procedure. A hypodermic needle is passed into the lump, and samples
of tissues are taken. Often several passes with the needle are
required. There is little pain afterward and very few complications
from the procedure occur. This test gives the doctor more information
on the nature of the lump in your thyroid gland and specifically
will help to differentiate a benign from a malignant thyroid
mass.
Abnormalities of thyroid function (hyper or hypothyroidism)
are usually treated medically. If there is insufficient production
of thyroid hormone, this may be given in a form of a thyroid
hormone pill taken daily. Hyperthyroidism is treated mostly by
medical means, but occasionally it may require the surgical removal
of the thyroid gland.
If there is a lump of the thyroid or a diffused enlargement
(goiter), your doctor will propose a treatment plan based on
the examination and your test results. Most thyroid "lumps" are
benign. Often they may be treated with thyroid hormone, and this
is called "suppression" therapy. The object of this
treatment is to attempt shrinkage of the mass over time, usually
three-six months. If the lump continues to grow during treatment
when you are taking the medication, most doctors will recommend
removal of the affected lump.
If the fine needle aspiration is reported as suspicious for
or suggestive of cancer, then thyroid surgery is required.
Thyroid surgery is an operation to remove part or all of the
thyroid gland. It is performed in the hospital, and general anesthesia
is usually required. Usually the operation removes the lobe of
the thyroid gland containing the lump and possibly the isthmus.
A frozen section (an immediate microscopic reading) may or may
not be used to determine if the rest of the thyroid gland should
be removed. Sometimes, based on the result of the frozen section,
the surgeon may decide to stop and remove no more thyroid tissue,
or proceed to remove the entire thyroid gland, and/or other tissue
in the neck. This is a decision usually made in the operating
room by the surgeon, based on findings at the time of surgery.
Your surgeon will discuss these options with you preoperatively.
After surgery, you may have a drain (a tiny piece of plastic
tubing), which prevents fluid from building up in the wound.
This is removed after the fluid accumulation is minimal. Most
patients are discharged one to three days after surgery. Complications
after thyroid surgery are rare. They include bleeding, a hoarse
voice, difficulty swallowing, numbness of the skin on the neck,
and low blood calcium. Most complications go away after a few
weeks. Patients who have all of their thyroid gland removed have
a higher risk of low blood calcium post-operatively.
Patients who have thyroid surgery may be required to take thyroid
medication to replace thyroid hormones after surgery. Some patients
may need to take calcium replacement if their blood calcium is
low. This will depend on how much thyroid gland remains, and
what was found during surgery. If you have any questions about
thyroid surgery, ask your doctor and he or she will answer them
in detail.
© 2004 AAO-HNS/AAO-HNSF
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What is Your Thyroid Gland?