Does sleeping badly, sweating a lot, having mood swings and losing weight without meaning to sound familiar to you? If the answer is yes, there’s a chance you’re dealing with an overactive thyroid (hyperthyroidism).
It’s quite common – in the US, overactive thyroid affects about 1 in 100 people over 12, and women are around 10 times more likely to get it than men.
Dealing with the day-to-day symptoms can be frustrating, worrying and exhausting – especially if you’re struggling to sleep at night. Maybe you’ve had to stop wearing light coloured clothes in public because of heavy sweat marks, you’re sick of needing the loo and trying to eat differently to offset diarrhoea, or your nervous energy and mood swings are making you feel like you’ve got a split personality?
“We don’t want symptoms to get in the way of you living your life to the full. And the good news is that an overactive thyroid can be easily treated with effective medicines,” explains Dr Ann Nainan. “Plus, there are self-care tips you can follow to make your symptoms easier to cope with.”
So read on to find out everything you need to know about overactive thyroid, including the signs to look out for, what you can do about it, and when to see a doctor.
What is an overactive thyroid?
If you have an overactive thyroid, it means your thyroid gland in your neck makes too much of the thyroid hormones your body needs. This is the opposite of an underactive thyroid (hypothyroidism), when it doesn’t make enough hormones. (Read more about your thyroid gland and how it works.)
Thyroid hormones help to control your body’s metabolism, so having too much of these hormones in your blood can make your body do basic things faster than normal. For example, your heart can start beating too fast, so you might feel more stressed or on edge, or your body might start digesting food faster, which can affect how many times you need the loo and cause you to lose weight without meaning to.
If an overactive thyroid isn’t treated, over time it can lead to other health issues, such as heart problems and weakened bones (osteoporosis). But with the right treatment, you can easily manage your condition and feel healthy.
Who’s more likely to get an overactive thyroid?
You can develop an overactive thyroid at any age or time in your life, but some things may mean you’re more likely to get it:
- it’s much more common if you’re a woman
- in England, about 1 in 50 women are living with an overactive thyroid, while in the US, around 1 in 8 women will be affected by thyroid problems at some point
Other things that can make overactive thyroid more likely include:
- being white or Asian – it’s less common in African-Caribbean people
- your age – it’s more likely the older you are
- being pregnant within the last 6 months
- a family history of thyroid problems
- certain long-term (chronic) conditions, including diabetes, pernicious anaemia and a hormone disorder called primary adrenal insufficiency
- eating lots of iodine-rich foods, such as seaweed and seafood, or taking medicines that contain iodine
- smoking
Overactive thyroid signs and symptoms
There are lots of possible overactive thyroid symptoms, but you probably won’t get all of them. They may be mild or severe, and can come on slowly over time, or appear quite suddenly.
Possible symptoms include:
- having lots of nervous energy and finding it hard to sit still (hyperactivity)
- mood swings – including feeling anxious, irritable or nervous
- finding it hard to sleep (insomnia)
- feeling tired all the time (fatigue)
- feeling like you have weak muscles
- needing to pee or poo more often than normal
- having diarrhoea or greasy poos that are difficult to flush (steatorrhoea)
- being sensitive to heat
- sweating a lot
- losing weight without meaning to – even though you may feel more hungry than usual
- low sex drive (libido)
If you have diabetes, an overactive thyroid can make your symptoms worse, and you may feel very thirsty and tired.
Other signs of an overactive thyroid to look out for include:
- a swelling in your neck – caused by an enlarged thyroid gland (goitre)
- an unusually fast heart rate (palpitations)
- trembling or shaking (tremors)
- warm, moist skin
- redness on the palms of your hands
- changes to your finger and toe nails
- hives (urticaria)
- patchy hair loss (alopecia)
- twitches in your face, arms and legs
- red and dry eyes, or vision problems
Many of these can also be symptoms of other conditions, which can make it difficult to know if you have an overactive thyroid. This can be frustrating, as you’ll want to know what’s happening, which is why it’s important to see a doctor for a diagnosis.
If you’re not sure if you need to see a doctor, try using our Smart Symptom Checker to help you work out your best next step.
Overactive thyroid symptoms in women
Having an overactive thyroid means you have an imbalance of hormones – so for women, this can affect how the reproductive system works. As well as the symptoms above, this may cause:
- very light or irregular periods, or no periods at all
- lack of ovulation, which can lead to fertility problems
- more severe morning sickness if you’re pregnant
- early menopause – when your periods stop before you’re 45
What causes an overactive thyroid?
There are a few different things that can lead to your thyroid gland pumping out too many thyroid hormones.
The most common causes are:
- Graves’ disease – an ‘autoimmune’ condition where your immune system attacks your thyroid gland by mistake, damaging it and causing it to make too many thyroid hormones. Graves’ disease often runs in families and commonly affects women between the ages of 20 and 40
- thyroid nodules – lumps that can develop on your thyroid gland, which are usually non-cancerous (benign). These can stop the gland from working normally, which can cause it to make too many thyroid hormones
Less common causes include:
- pregnancy – being pregnant can cause high levels of a substance called human chorionic gonadotropin (hCG) to collect in your body, which changes your levels of thyroid hormones. It happens most often in early pregnancy, or if you’re pregnant with twins or triplets
- medication – some medicines, such as amiodarone (which is used to treat an irregular heartbeat), can cause an overactive thyroid because they contain iodine
- thyroiditis – this is when your thyroid gland becomes inflamed, which can sometimes cause it to make extra hormones
- pituitary adenoma – this is a non-cancerous tumour of your pituitary gland, which can affect the hormones made by your thyroid gland
- thyroid cancer – it’s rare, but a cancerous tumour can sometimes cause an overactive thyroid by affecting how your gland works
Can an overactive thyroid cause other health issues??
If an overactive thyroid isn’t treated, it can sometimes lead to other health conditions over time. These include:
- eye problems – if your overactive thyroid is caused by Graves’ disease and it isn’t treated, you may get eye problems known as thyroid eye disease or Graves’ ophthalmopathy. This means your eyes will often feel dry and gritty, and become sensitive to light. You might also get double vision, notice more tears or feel pressure behind your eyes, and your eyes may even start bulging from their sockets
- pregnancy problems – an overactive thyroid can increase the risk of issues such as miscarriage, pre-eclampsia and going into labour early
- underactive thyroid – treatment for an overactive thyroid can sometimes cause your thyroid hormones to go the other way and become too low, leading to an underactive thyroid (hypothyroidism)
Other, less common complications of an overactive thyroid include:
- atrial fibrillation – when your heartbeat is irregular and often very fast
- osteoporosis – when your bones become weak and fragile
- heart failure – when your heart isn’t able to pump blood around your body properly
How to cope with the symptoms of an overactive thyroid
The symptoms of an overactive thyroid can really affect how you live your life, which might make you feel low, frustrated and alone. But the condition can be easily treated so if you think you might have a thyroid problem, speaking to a doctor should be your first step. They can help you get a diagnosis and advise on the best treatment for you.
If you do get diagnosed with an overactive thyroid, the good news is there are lots of self-care measures you can take at home to help you cope. Read about how to live with a thyroid problem and the best diet for an overactive thyroid.
When to see a doctor about overactive thyroid
If you think you have symptoms of an overactive thyroid, or you notice a neck lump, speak to a doctor as soon as you can. They can help you work out exactly what’s going on – even if it’s not hyperthyroidism – and find the right treatment to help you manage your symptoms.
You should see a doctor as an emergency if you:
- have symptoms of a thyroid storm, as mentioned below
- have trouble breathing
- have problems swallowing
- have palpitations that don’t go away or keep coming back
- can’t to fully close your eyes
- find it hard to move your arms or legs
What is a thyroid storm?
In rare cases, untreated hyperthyroidism can lead to a very serious condition called a thyroid storm. It can be triggered by an infection, damage to your thyroid gland, not taking your medicine properly, or pregnancy.
Symptoms of a thyroid storm include:
- a very fast heartbeat
- a high temperature
- loose watery poos (diarrhoea) and being sick (vomiting)
- yellowing of the skin and eyes (jaundice)
- feeling angry and confused
- losing consciousness
If you have these symptoms, get emergency medical help.
How to prepare for your appointment
Before you speak to your doctor, think about the sorts of questions you might want to ask, and make sure you have a list of all of your symptoms. This can help you get the right diagnosis and treatment more quickly.
Read more about how to get ready for your appointment.
How is overactive thyroid diagnosed?
Getting a diagnosis for an overactive thyroid might not happen straight away, mainly because a lot of the symptoms could also be caused by other conditions, so it takes a bit of detective work.
Your doctor will use different checks, tests and scans to find out what’s causing your symptoms, including:
- a physical exam – your doctor might feel the outside of your neck to see if your thyroid is swollen, bumpy or tender. They might also check to see if your eyes are swollen or red, or if you have a fast heartbeat
- thyroid blood tests – a thyroid function blood test checks your levels of thyroid hormones, including thyroid stimulating hormone (TSH) and thyroxine (T4)
- other blood tests – you may have blood tests to look for anti-thyroid antibodies, which can mean you have Graves’ disease. Your erythrocyte sedimentation rate (ESR) can also be measured – this checks for inflammation in your body, which can be caused by thyroiditis. Other tests might also be done before starting medication like checking your blood count and liver function
- thyroid scan – this looks for thyroid nodules. You’ll be given a small amount of a radioactive substance, to see how much is absorbed by your thyroid gland
- thyroid ultrasound scan – this test uses high-frequency sound waves to take a closer look at your thyroid gland to detect lumps or nodules
Overactive thyroid treatment
Although you’ll need medication and sometimes an operation to treat an overactive thyroid, self-care can help you deal with some of the symptoms and learn to cope with having a long-term condition. Read about ways to help ease your thyroid symptoms.
Treatment can include:
- beta-blockers – these are often started while you’re waiting to see a specialist. They can slow your heart rate and help with other symptoms of hyperthyroidism like anxiety, tremors and palpitations
- anti-thyroid medicines called thionamides such as carbimazole and propylthiouracil
- radioactive iodine treatment
- surgery on your thyroid gland
How long your treatment takes will depend on what’s causing your overactive thyroid and the type of treatment you need. But if you’re given thionamide medicine, your hormone levels should drop within 6 to 12 weeks.
Each treatment comes with possible side effects and other things to be aware of, which your doctor will talk to you about. Read more about treatment for an overactive thyroid.
If you have thyroid eye disease, you may be referred to see an eye specialist (ophthalmologist). While you wait for an appointment, your doctor might:
- offer you artificial tears to help keep your eyes moist
- suggest you wear sunglasses during the day and eye protectors to sleep
- suggest raising the head of your bed to relieve morning eyelid swelling
The Thyroid Eye Disease Charitable Trust can offer more advice and support.
Can overactive thyroid be cured?
Once you’ve been diagnosed by a doctor, an overactive thyroid is a very manageable condition.
- a single radioactive iodine treatment may completely cure your overactive thyroid, although there is a chance you could be left with an underactive thyroid and need to take long term medication for this
- medication can often bring your levels of thyroid hormones back to normal
- in other cases, for example if radioactive treatment or surgery isn’t suitable for you, you may need to keep taking anti-thyroid medicine for many years, or even for the rest of your life
If having a long term condition is making you feel low and frustrated, it can help to know that you’re not alone. You can chat with other people going through the same thing, and get more in-depth support from these organisations:
Doctor’s tips
Answered by Dr Adiele Hoffman
“Use your smartphone to your advantage and set up a regular notification that reminds you to take your medication. Set it for a time when you know you'll have easy access to it, like when you first wake up, and keep your medication by your bed. If you need to take it at a tricky time of day, keep a strip of medication in your purse.”
“There's a lot of overlap between menopause symptoms and hyperthyroidism – feeling hot, anxious and experiencing changes to your periods are common in both. Trying to distinguish between the 2 can be hard, even for doctors, so if you're not sure or you have more unusual symptoms that menopause shouldn't normally cause, like losing weight, it's always best to talk to your doctor. They can consider if blood tests will give you the answer.”
