Thyroid cancer is when abnormal cells in the thyroid gland start to divide and grow in an uncontrolled way. Without treatment, cancer cells can eventually grow into surrounding healthy tissues and may spread to other areas of the body.
The thyroid gland sits in the throat. This 2 minute video describes the different parts of the throat.
We call this area the throat but in fact it includes a number of different parts. The thyroid gland, trachea, nasopharynx, oropharynx, larynx and the oesophagus.
At the top of the throat is the nasopharynx or the back of the nose. When we breathe in air passes through the nasopharynx into the lungs.
The next part of the throat is the oropharynx or the back of the mouth. It includes the soft palate, the back wall of the throat, the tonsils and the back part of the tongue.
The larynx, or the voice box, is the part of the throat that contains the epiglottis and the vocal cords. As we breathe in air passes through the vocal cords to make sound. When we swallow the epiglottis closes to prevent food and liquid entering the airway, allowing the food to pass into the oesophagus or food pipe.
Surrounding the larynx is the hypopharynx and on either side of the larynx are the piriform sinuses. They help to channel food into the oesophagus.
The trachea or windpipe starts in the throat area. It is the tube that air moves through as air passes in and out of the lungs.
The thyroid gland sits just below the larynx in front of the trachea. It makes hormones that help the body to work normally.
The parathyroid glands are just behind the thyroid gland. They help control the amount of calcium in the body.
And finally, there are lymph glands throughout this part of the body. Our lymph glands are part of our immune system and help us to fight infections.
For more information about cancers that start in the throat and symptoms of throat cancer go to cruk.org/throat
The thyroid gland
The thyroid is a small butterfly shaped gland that makes and releases hormones. It’s found at the front of your neck in the lowest part, just behind the small hollow where your collar bones meet. You can’t usually feel a thyroid gland that is normal.
The thyroid gland is in 2 halves called lobes. They are connected together by a thinner bridge of thyroid tissue. The bridge is called the isthmus.
A thyroid cancer is usually found in just one lobe. But some types of thyroid cancer can be found in both lobes.
What does the thyroid gland do?
The thyroid gland makes hormones which affect the way your body works.
T3 and T4
T3 (tri iodothyronine) and T4 (thyroxine) are the main hormones that your thyroid gland makes. They help to control your metabolic rate which is the speed of your body processes. For example, these hormones help to control your digestion, muscles and heart.
You might put on weight and feel very tired and lacking in energy if your thyroid gland doesn't make enough T3 and T4.
You can lose weight, despite an increased appetite, if your thyroid gland makes too much of these hormones. You might also feel anxious and find it difficult to relax.
Calcitonin is another hormone produced by the thyroid gland. It helps to control the amount of calcium circulating in the blood. Calcitonin works with a hormone called parathyroid hormone to do this.
Parathyroid hormone is made by parathyroid glands. These sit behind and are attached to the thyroid gland.
Too much calcium can make you feel sick and drowsy. Too little can cause nerve problems, such as pins and needles, making muscles twitch and jerk.
The parathyroid glands are left behind if you have your thyroid gland removed. But they can be affected by the operation and may take a while to get back to normal.
Your doctor will check your calcium levels regularly and might give you calcium supplements if needed.
How common is thyroid cancer?
Thyroid cancer is quite rare. Around 3,700 people are diagnosed in the UK each year. In the UK, only 1 out of every 100 people diagnosed with cancer (1%) has thyroid cancer. It’s more common in women than in men.
There are factors that can increase the risk of developing thyroid cancer, including radiation and some types of non cancerous thyroid conditions.