Travelling with an Overactive Thyroid

You can usually travel abroad with an overactive thyroid if your condition is well controlled. Before travelling, speak to your GP or specialist if you have ongoing symptoms or are receiving treatment; make sure you have enough medication and check whether any blood tests are due. It's also important to understand how to manage your symptoms while away and arrange suitable travel insurance that covers your pre-existing medical condition.

An overactive thyroid, also known as hyperthyroidism or thyrotoxicosis, means your thyroid gland produces too much thyroid hormone. These hormones help control your metabolism, heart rate and body temperature. When you have too much, your body can work faster than normal, causing a range of symptoms.

An overactive thyroid is more common in women than men. One of the main causes is Graves’ disease, an autoimmune condition that makes your thyroid produce too much hormone. Other causes include thyroid nodules and inflammation of the thyroid gland.

Symptoms can include feeling anxious or restless, losing weight despite having a good appetite, sweating more than usual, feeling unusually hot, having diarrhoea or experiencing a fast or irregular heartbeat. You may also feel tired, weak or shaky.

If your thyroid is well controlled, having an overactive thyroid should not necessarily stop you from travelling abroad. However, it is important to plan ahead, especially if you have recently been diagnosed, have ongoing symptoms or are having treatment.

What treatments are available?

Your treatment will depend on the cause of your overactive thyroid and your individual circumstances.

• Medication: Carbimazole is commonly prescribed to reduce the amount of thyroid hormone your gland produces. Propylthiouracil is another option in certain circumstances. You may also be prescribed a beta-blocker to help control symptoms such as a rapid heartbeat and trembling.
• Radioactive iodine: This treatment involves swallowing a capsule or liquid containing radioactive iodine (the dose is tiny, so it’s not dangerous to you). It gradually destroys some of the thyroid tissue, reducing hormone production. You will receive specific instructions about limiting close contact with children and pregnant women afterwards.
• Surgery: In some cases, an operation to remove part or all of your thyroid gland may be recommended.

These treatments can sometimes leave you with an underactive thyroid, meaning your body no longer produces enough thyroid hormone. If this happens, you may need lifelong treatment with levothyroxine.

Treatment can take time to work, and regular blood tests are often needed to check your hormone levels and adjust your medication. Your GP or endocrinologist can advise you when your condition is sufficiently stable for travel.

My Top Travel Tips for an Overactive Thyroid

Having an overactive thyroid does not automatically mean you need to cancel your holiday, but the tips below can help you travel more confidently and reduce the risk of problems while you are away.

1. Check that your condition is under control

Before booking or travelling, consider how well your symptoms are controlled. If you have a persistently fast heartbeat, troublesome palpitations, worsening breathlessness or significant weakness, speak to your GP or specialist before travelling.

2. Plan your medication carefully

If you take carbimazole, a beta-blocker or another regular medicine, order your repeat prescription well in advance. Take enough medication for the whole trip, plus a reasonable extra supply in case your return is delayed. Keep medicines in their original packaging and carry them in your hand luggage, rather than relying on checked baggage.

Check the rules for taking prescription medicines into your destination country, particularly if you are travelling long-haul or visiting several countries. See our article on taking medication abroad for more details.

If you cross time zones, ask your pharmacist how best to maintain your usual dosing schedule. Do not change your dose or stop taking your medication without medical advice.

3. Carry your medical information

Take a copy of your repeat prescription and a list of your medicines, including their doses. A letter from your GP or specialist explaining your diagnosis and treatment can also be useful, particularly if you need medical care abroad.

Keep these details, along with your travel insurance information and emergency contacts, somewhere accessible. If you have a medical emergency, this information can help local healthcare professionals understand your condition and treatment.

4. Take extra care in hot weather

An overactive thyroid can make you more sensitive to heat and cause excessive sweating. Hot weather, particularly in tropical destinations, can make it harder to stay comfortable and hydrated.

Drink water regularly, seek shade during the hottest part of the day and wear light clothing. Avoid pushing yourself too hard when sightseeing, walking or taking part in excursions.

If you develop diarrhoea, you may lose extra fluid, so pay attention to hydration. If you become dizzy, unusually weak or feel your heart racing, stop what you are doing and seek medical advice if symptoms persist or are severe.

READ MORE: Medical Conditions and Hot Weather

5. Be aware of your heart rate

Too much thyroid hormone can cause a rapid or irregular heartbeat. In some people, an untreated or poorly controlled overactive thyroid can lead to atrial fibrillation, a heart rhythm problem that increases the risk of stroke.

If you already experience palpitations, discuss these with your doctor before travelling. Take any prescribed medication as directed, and avoid assuming that a racing heart is simply due to excitement, heat or walking.

Seek emergency medical help if you develop chest pain, severe breathlessness, fainting or a very fast or irregular heartbeat accompanied by feeling seriously unwell.

READ MORE: How to Find Medical Care Abroad

6. Know the warning signs of a thyroid emergency

A rare but life-threatening complication of an overactive thyroid is a thyroid storm. It can cause a very high temperature, a rapid heartbeat, severe agitation or confusion, and sometimes loss of consciousness.

If you develop these symptoms, call the local emergency number immediately. In the UK, call 999. It is particularly important to seek prompt medical advice if your symptoms suddenly become much worse or you develop an acute illness while travelling.

7. Watch for serious side effects of carbimazole

Carbimazole can rarely cause a serious reduction in white blood cells, making it harder for your body to fight infections.

If you develop a sore throat, mouth ulcers, a high temperature or flu-like symptoms while taking carbimazole, seek urgent medical advice. You may need a blood test to check your white blood cell count. Do not simply assume you have picked up a routine travel infection.

Your doctor can advise you what to do about your next dose while you are being assessed.

8. Check your blood test schedule

When you first start treatment, or when your dose changes, you may need frequent blood tests. Your thyroid hormone levels can take time to settle, so do not assume you will be ready for a long trip simply because you feel better.

Before travelling, check with your GP or specialist whether you need blood tests or an appointment while you are away. If you are going on a lengthy trip, ask whether suitable monitoring can be arranged at your destination.

9. Take special care after radioactive iodine treatment

If you have recently had radioactive iodine treatment, ask your specialist when it is safe to travel. You will be given individual instructions about avoiding prolonged close contact with children and pregnant women for a period after treatment.

Radioactive iodine can also trigger radiation detectors (not metal detectors) at airports or other transport facilities for a period after treatment. Ask your hospital whether you should carry a letter confirming the treatment and when it took place.

10. Arrange suitable travel insurance

If you are travelling abroad from the UK, arrange travel insurance that covers your overactive thyroid and any related complications. Declare your condition, any other medical conditions, your medication and any pending tests or treatment when asked.

Check the policy carefully, including whether it covers emergency medical treatment, hospital stays and medical repatriation if you cannot return home as planned.

A valid UK Global Health Insurance Card (GHIC), or an in-date European Health Insurance Card (EHIC), may give you access to necessary state healthcare in participating European countries. However, neither card replaces travel insurance or covers every healthcare cost.

If you plan to take part in activities such as scuba diving, trekking or other adventure sports, check whether these are covered too.

Enjoying your holiday with an overactive thyroid

An overactive thyroid need not prevent you from enjoying a holiday abroad. The key is to make sure your condition is well managed, take your medication as prescribed and arrange any necessary blood tests before you leave.

Pack your medicines and medical information carefully, protect yourself from excessive heat and know when to seek help. Make sure your travel insurance covers your condition and the activities you plan to enjoy.

With sensible preparation and advice from your healthcare team, you can reduce the risk of unexpected problems and enjoy your time away with greater peace of mind.