This section is for teens and young adults. It’s about a type of cancer called thyroid cancer.

We also have more information about:

If you’re looking for information about thyroid cancer in people of all ages, read our thyroid cancer section.

Papillary and follicular thyroid cancers are the most common types of thyroid cancer in young adults. If you'd like to find out about a different type of thyroid cancer you could talk to Macmillan Cancer Support.

It’s important to remember that thyroid cancer in young people can be successfully treated. Most young people are completely cured.


The first sign of thyroid cancer is usually a painless lump or swelling in the front of the neck that gradually gets bigger.

Less common symptoms are:

  • a hoarse voice that doesn't get better
  • difficulty swallowing or breathing

If you have any of these symptoms, it's important to speak to a doctor.

Remember – these symptoms can happen for lots of reasons other than cancer.

What are the causes of thyroid cancer?

It's unknown exactly what causes thyroid cancer. But research into possible causes is going on all the time. Some things called risk factors increase your chance of developing cancer. But having these doesn’t mean you’ll get cancer.


Genes are the biological information in each cell that we inherit from our parents. Genes affect the way we look (for example, our eye colour) and how our bodies grow and work. Some rare genetic conditions that run in families can increase the risk of thyroid cancer. But fewer than 1 in 10 cases of cancer are caused by an inherited faulty gene.


If you were exposed to radiation or had radiotherapy treatment to the neck area when you were younger, you may be at a higher risk of developing thyroid cancer many years later.

If you're worried about thyroid cancer

If you think you might have some of these symptoms you should go straight to your GP. They'll be able to talk to you about your symptoms. If they think the symptoms could be because of cancer, they can do tests to find out more.

The thyroid and types of thyroid cancer

The thyroid is a small gland in the front of the neck just below the voice box (larynx). It is made up of 2 parts, or lobes, 1 on each side of the neck. It's part of a network of glands throughout the body that make up the endocrine system. This system is responsible for producing the body’s hormones that help to control and influence various body functions.

The thyroid produces 2 hormones:

  • thyroid hormone that controls your metabolism
  • calcitonin that helps to control the calcium levels in your body

Types of thyroid cancer

There are 4 main types of thyroid cancer:

  • papillary is the most common type of thyroid cancer – it’s usually slow-growing
  • follicular is the second most common type – it's also usually slow-growing
  • medullary is a rare type of thyroid cancer which sometimes runs in families
  • anaplastic is another rare type of thyroid cancer, which is more common in older people

Young people are mostly affected by the papillary and follicular types.

Rarely other types of cancer occur in the thyroid gland such as lymphoma, or other cancers that have spread from another part of the body.

This section is for teens and young adults. It’s about a type of cancer called thyroid cancer.

We also have information on:

If you’re looking for information about thyroid cancer in people of all ages, read our thyroid cancer section.

Having tests for thyroid cancer

This information is for teenagers and young adults who may be having tests to find out if they have thyroid cancer.

If you think you might have some of the symptoms of thyroid cancer, you should talk to your GP. If they think the symptoms could be because of cancer, they can do tests to find out more.

Visiting your GP

When you go to your GP they will usually examine you and arrange some blood tests. There may be a number of reasons why you have these symptoms. If your GP is concerned that you may have thyroid cancer they will make an appointment for you with a specialist at the hospital.

At the hospital

You’ll probably be seen by lots of people at the hospital during and after the tests they do to find out what is happening to you. They work as a team and all have an important part in your care, even though you may only meet some of them.

They may include:

  • a doctor who specialises in thyroid problems (endocrinologist)
  • a surgeon who specialises in thyroid surgery
  • a pathologist who looks at blood and tissue samples to diagnose diseases
  • a cancer specialist (oncologist)
  • an X-ray specialist (radiologist)
  • a clinical nurse specialist

Your doctor will examine you and arrange for more detailed tests, which may include an ultrasound, a fine needle aspiration (FNA) or a biopsy.

An FNA involves having a very small needle placed into your thyroid gland to remove a few cells for the pathologist to look at under the microscope.

A biopsy involves removing a small piece of the thyroid to be analysed. You might have a general anaesthetic and so will be asleep when it is done. You may only need a local anaesthetic, which numbs the area. There is more information about having an anaesthetic in the surgery section.

If the biopsy shows that it is thyroid cancer you will have some other tests to check the size of the tumour and whether it has spread. Macmillan Cancer Support has information on these tests. These tests may include:

  • a chest
  • X-ray to check your lungs
  • a CT, MRI or PET scan
  • a radioisotope scan

You won’t necessarily need all of these tests. It will depend on the results of the first ones.

Having tests and waiting for the results can be an anxious time. Talking about how you feel and getting support from your family, friends, specialist nurse or doctor can help.

We have more information about:

If you're looking for information about thyroid cancer in people of all ages, read our general thyroid cancer information.

Treating thyroid cancer

It’s important to remember that thyroid cancer in young people can be successfully treated. Most young people are completely cured. If the tests you’ve had show you have thyroid cancer, your team of specialists will discuss treatment with you.


Surgery to remove the thyroid gland is the main treatment for thyroid cancer. You might hear the doctors talk about a thyroidectomy, which is the medical name for the operation. Sometimes the surgeon will only need to remove part of your thyroid.

Lymph nodes

In the neck, close to the thyroid, there are lymph nodes. These are part of the body’s immune system and help fight infection. Sometimes cancer cells settle in these lymph nodes, so the surgeon might remove some or all of the nodes as well. They may also remove some tissue from the area around the thyroid if they suspect that there are any cancer cells there.

After the operation

You will probably need to spend a few days in hospital after the operation. There will be a scar on your neck – usually just above the collarbone. Sometimes you can have a low calcium level in your blood or a hoarse voice after the operation. You may need to take tablets to replace the thyroid hormone.

The tissue removed will be carefully looked at under the microscope. Sometimes another operation is needed after this. The results will help your doctors decide if you need radioactive iodine treatment and other treatments. Your team will talk through the results of the operation with you.

You may feel really shocked and scared by the thought of having this operation. But it does give a really good chance of a cure. Your specialist will talk things over with you in detail and make sure that you fully understand what’s involved. If you want to know more about what happens when you go in for an operation, there’s lots more information in the general surgery section.

Radioactive iodine

If you’ve been told that you need to have treatment with radioactive iodine, you may be worried about what’s going to happen. Knowing what to expect can help.

Your doctors and nurses will also explain things to you and give you support.

How does it work?

There's a mineral called iodine in the bloodstream. Normal thyroid tissue takes iodine from the bloodstream and uses it to make thyroid hormones. Some thyroid cancers can take iodine from the bloodstream too.

Radioactive iodine is often used after surgery when the whole thyroid gland has been removed. Any thyroid cancer cells left behind soak up the iodine which contains high doses of radiation. This helps to destroy them. Radioactive iodine doesn’t usually affect other parts of the body because other cells don’t take up iodine the way thyroid cells do.

How is it given?

You may have radioactive iodine as a capsule, as a drink or as an injection into a vein in your arm through a cannula.

Preparing for treatment

There are 2 ways to prepare your body for the radioiodine treatment, either you'll:

  • be given an injection of a drug called thyrotropin alfa (Thyrogen®)
  • need to stop taking your thyroid hormone tablets 2 to 4 weeks before the treatment

Some people won’t be started on thyroid hormones until after surgery and radioactive iodine treatment. You’ll probably feel very tired during this time. But, if you are not having the injections, it’s important that you stop taking thyroid hormones or the radioactive iodine treatment won’t work.

For 2 weeks before treatment, you’ll be asked to eat a low-iodine diet and avoid certain foods. This encourages the body to use up its stores of iodine. Then when the radioactive iodine is given, the cancer cells will soak it up because the amount of iodine in the body is so low. You’ll be given information about what foods you should eat and what to avoid.

You can’t have this treatment if you are pregnant. If there is any chance of this tell your team and they can test you.

What happens during treatment?

This treatment makes you slightly radioactive for several weeks. Your body will gradually get rid of the radioactivity through your wee, sweat and saliva. You will be kept in hospital when the radioactivity is highest, which is usually between 1 to 5 days. You will be looked after in a side room on the ward, either on your own or with someone else having the same treatment.

During this treatment, the amount of contact you can have with your friends, family and the nurses will be limited, to protect them from exposure to the radiation. Anyone pregnant or younger than 18 usually isn’t allowed to visit. This can make you feel lonely. You will be able to keep in touch with your friends and family by phone and internet. There should be plenty of books, magazines, DVDs, computer games and a TV in the room. You can take in a few of your own things in to help pass the time. Ask your team whether you can take a computer or an MP3 player into the room with you. Anything that comes back out of your room will be checked for radiation levels. Sometimes your things may have to be kept on the ward for a while if the radiation levels are high. But they’ll be returned to you when they’re safe again.

What happens after treatment?

Once your radiation levels are safe, you’ll be allowed home. You’ll also be able to start eating your usual foods again. Check with the staff about what you can and can’t do when you get home. There are likely to be some precautions to take for up to a few weeks.

You might need a scan shortly after your treatment. This shows if you need more radioiodine treatment. If you need more treatment it is usually given every 3 to 6 months.

Your fertility won’t be affected by the treatment. But it’s safer not to become pregnant or get someone else pregnant during treatment, and for a year after. You should avoid all sex and open-mouthed kissing for a few days after treatment.

Travelling on public transport can be restricted just after treatment, so you may not be able to go on holiday just after treatment. For a few months after treatment you might set off the alarms at the security gates. If you are planning a holiday, discuss it with your team.

External beam radiotherapy

You may also have external beam radiotherapy. For this treatment you come to hospital and lie on a bed in the radiotherapy department for about 10 to 20 minutes every day. You will have treatment every weekday for several weeks. It is like having an X-ray, so it doesn’t hurt and you cannot feel it. 

Hormone therapy after treatment for thyroid cancer

If you’ve had all your thyroid gland removed, your body can’t produce thyroid hormones anymore. Without these hormones, your metabolism slows down. This can cause dry skin and hair, tiredness, poor concentration and lack of energy.

What can help?

These hormones can be replaced by taking tablets. You’ll need to take them for the rest of your life. The usual long-term hormone treatment is thyroxine (levothyroxine) and you normally start taking it once your radioactive iodine treatment is finished.

As well as replacing the hormones you’re missing, thyroxine can also help stop papillary or follicular thyroid cancer coming back. So if you have only had part of your thyroid gland removed you may still need to take thyroid hormone tablets.

Blood tests

You’ll need to have your blood checked regularly to monitor the hormone levels. It can sometimes take months to find the right dose of thyroxine for you. But once the right dose is found, there shouldn’t be any side effects, because they are simply replacing normal thyroid hormones.

It’s important to remember to take your tablets every day. It can help to take them at the same time every day so you get into a routine.

Macmillan Cancer Support has more general information about radiotherapysurgery and radioactive iodine treatment. This information is written for people of all ages, not just young adults with thyroid cancer.

This information is for teenagers and young adults and is about having treatment for thyroid cancer.

We have more information about:

If you're looking for information about thyroid cancer in people of all ages, read our thyroid cancer information.

Last updated:
08 December 2022

Search for cancer support services near you