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
The thyroid is a gland that makes and releases hormones. It’s found at the base of your neck, at the front, just behind the small hollow where your collar bones meet.
The thyroid gland is in 2 halves, connected by a thinner bridge of thyroid tissue. The bridge is called the isthmus.
The 2 halves are called the lobes. Usually a cancer is found only in one lobe. But very small areas of cancer (microcarcinomas) of papillary thyroid cancer can be found in both lobes. Another type called medullary thyroid cancer can develop in both lobes.
What does the thyroid gland do?
The thyroid gland makes the following hormones.
T3 and T4
T3 (tri iodothyronine) and T4 (thyroxine) are hormones that help control your metabolic rate - the speed of your body processes.
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 works in partnership with another hormone called parathyroid hormone. Parathyroid hormone is made by parathyroid glands. These sit behind and are attached to the thyroid gland.
Calcitonin and parathyroid hormone control the amount of calcium circulating in your blood. Too much calcium can make you feel sick and drowsy. Too little can cause nerve problems, such as pins and needles, and 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 3,500 people are diagnosed in the UK each year. 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.