Thyroid Disorders
Sources consulted
This article is original patient-education content.
- NICE—Thyroid disease: assessment and management. NG145(2019)
- NHS—Underactive thyroid (hypothyroidism)(2023)
- WHO—Thyroid disorders(2023)
- ATA—American Thyroid Association guidelines(2023)
Based on international clinical guidelines
Overview
Your thyroid is a small, butterfly-shaped gland that sits at the front of your neck. It makes hormones — chemical messengers — that control how fast or slow almost every part of your body works, from your heart rate and digestion to your mood and energy levels. A thyroid disorder means this gland is not working quite right. It may be making too many hormones (called hyperthyroidism — an overactive thyroid), too few hormones (called hypothyroidism — an underactive thyroid), or it may develop growths or become inflamed. Each type affects the body in different ways, but most thyroid disorders are very manageable with the right care.
Key facts
- The thyroid gland controls your body's metabolism — the speed at which your cells use energy — so problems with it can affect almost every system in your body.
- There are several types of thyroid disorder, including an overactive thyroid (hyperthyroidism), an underactive thyroid (hypothyroidism), thyroid nodules (small lumps on the gland), thyroid inflammation (thyroiditis), and thyroid cancer.
- Most thyroid disorders are highly treatable, and many people live full, healthy lives with the right treatment and monitoring.
Thyroid disorders are very common worldwide. The British Thyroid Foundation estimates that around 1 in 20 people in the UK has some form of thyroid condition. Globally, hundreds of millions of people are affected. Underactive thyroid (hypothyroidism) is one of the most frequently diagnosed hormonal conditions in the world.
Thyroid disorders can affect anyone at any age, including children and older adults. However, they are significantly more common in women than in men — women are up to 10 times more likely to develop a thyroid condition. People with a family history of thyroid disease, those with certain autoimmune conditions (where the immune system mistakenly attacks the body's own tissues), and people who have had radiation to the neck area are at higher risk.
Symptoms
- Thyroid storm — a rare but life-threatening crisis of an extremely overactive thyroid. Signs include a very high fever, extreme agitation or confusion, a dangerously fast heart rate, and sometimes loss of consciousness. Call your local emergency number immediately.
- Myxoedema coma — a very rare but life-threatening complication of severe untreated underactive thyroid. Signs include extreme drowsiness, very low body temperature, slow breathing, and loss of consciousness. Call your local emergency number immediately.
- Sudden severe swelling in the neck that makes it hard to breathe or swallow — call your local emergency number immediately.
- Chest pain combined with a very fast or irregular heartbeat — call your local emergency number immediately.
- ⚠A lump or swelling in the neck that has appeared recently or is growing quickly — see a doctor the same day or go to an urgent care facility.
- ⚠Difficulty swallowing or a persistent feeling that something is stuck in your throat.
- ⚠A very rapid or irregular heartbeat that is new and makes you feel unwell.
- ⚠Sudden significant changes in mood, confusion, or mental state alongside other thyroid symptoms.
Common symptoms
- Unexplained weight gain or weight loss — without a clear change in diet or exercise
- Feeling unusually tired or exhausted all the time (fatigue)
- Feeling cold all the time or, on the other hand, feeling too hot and sweating more than usual
- Noticeable changes in heart rate — a slower heartbeat or a fast, fluttery heartbeat (palpitations)
- Constipation (difficulty passing stools) or, conversely, frequent loose stools and diarrhoea
- Dry skin, dry hair, or hair loss — including eyebrows thinning
- Muscle weakness, aches, or cramps
- Feeling low in mood, anxious, or irritable
- Difficulty concentrating or feeling mentally 'foggy'
- Changes in menstrual periods — irregular, heavier, or lighter periods in women
- A swelling at the front of the neck, sometimes called a goitre (a visibly enlarged thyroid gland)
Symptoms in children
- Slower growth than expected for their age
- Delayed puberty or puberty that starts earlier than normal
- Difficulty concentrating, or a noticeable change in school performance
- Feeling very tired or sluggish, or on the other hand being unusually restless and hyperactive
- Weight changes that do not match their eating habits
- A lump or swelling noticed at the front of the neck
Symptoms in older adults
- Symptoms are often subtler and can be mistaken for normal ageing — making diagnosis sometimes harder
- Unusual tiredness or weakness that affects daily activities
- Memory problems or difficulty thinking clearly (sometimes confused with early dementia)
- Changes in heart rhythm — including a new or worsening irregular heartbeat (called atrial fibrillation)
- Unexplained depression or low mood
- Constipation that is new or has gotten worse
- Increased sensitivity to cold temperatures
Causes
Main causes
- Autoimmune conditions — where the body's immune system accidentally attacks the thyroid gland. The most common causes of both underactive and overactive thyroid are autoimmune: Hashimoto's thyroiditis (which leads to an underactive thyroid) and Graves' disease (which leads to an overactive thyroid).
- Iodine levels — iodine is a mineral the thyroid needs to make its hormones. Getting too little or, less commonly, too much iodine can affect how the thyroid works. Iodine deficiency remains a global cause of goitre and underactive thyroid.
- Thyroid nodules — small lumps that grow on the thyroid. Most are harmless (benign), but occasionally they can cause the thyroid to produce too many hormones.
- Inflammation of the thyroid (thyroiditis) — this can be triggered by a viral infection, certain medicines, pregnancy, or radiation therapy.
- Previous thyroid treatment — surgery to remove part or all of the thyroid, or radioactive iodine treatment, can result in an underactive thyroid.
- Thyroid cancer — abnormal cells grow in the thyroid gland. It is one of the more treatable forms of cancer when caught early.
- Congenital thyroid problems — some babies are born with a thyroid gland that does not develop properly or does not make enough hormones (congenital hypothyroidism).
- Certain medicines — some medications can affect thyroid function as a side effect.
Risk factors
- Being female — women are much more likely to develop thyroid disorders than men
- A family history of thyroid disease or autoimmune conditions
- Personal history of an autoimmune condition such as type 1 diabetes or rheumatoid arthritis
- Age — risk increases with age, particularly for hypothyroidism
- Previous radiation therapy to the head, neck, or chest area
- Previous thyroid surgery
- Pregnancy or having given birth recently — postpartum thyroiditis (inflammation after childbirth) is more common than many people realise
- Living in an area where dietary iodine is low
- Smoking — which is linked to a higher risk of Graves' disease and thyroid eye disease
When to see a doctor
See a doctor urgently if:
- You notice a new lump, swelling, or visible change at the front of your neck
- You are having difficulty swallowing or breathing
- You develop a very fast, pounding, or irregular heartbeat
- You or someone you care for becomes confused, very drowsy, or loses consciousness and you suspect a thyroid problem
Book a routine appointment if:
- You have been feeling unusually tired, cold, or have gained weight without explanation for more than a few weeks
- You have unexplained anxiety, trembling hands, or heat intolerance (feeling too warm when others are comfortable)
- Your menstrual periods have changed significantly for no clear reason
- You have a family history of thyroid disease and have never been tested
- You are planning a pregnancy or are currently pregnant — thyroid health is important for both mother and baby
- You have an existing autoimmune condition and want to check your thyroid function
- You feel your mood, memory, or concentration has changed noticeably
Diagnosis
Diagnosing a thyroid disorder starts with your doctor asking about your symptoms and medical history, and doing a physical examination — including feeling the front of your neck to check the size and texture of your thyroid gland. The most important first test is usually a blood test. From there, your doctor may refer you to an endocrinologist (a specialist in hormonal conditions) or arrange further imaging or other tests depending on what is found.
Tests that may be done
- TSH blood test (thyroid-stimulating hormone test) — this is the key screening blood test. TSH is a hormone made by the brain that tells the thyroid how much to work. A high TSH usually means the thyroid is underactive; a low TSH often points to an overactive thyroid.
- Free T4 and Free T3 blood tests — these measure the actual thyroid hormones circulating in your blood. T4 (thyroxine) and T3 (triiodothyronine) are the main hormones the thyroid produces.
- Thyroid antibody tests — these check for proteins made by the immune system that target the thyroid. They help identify autoimmune causes such as Hashimoto's thyroiditis or Graves' disease.
- Ultrasound scan — a painless scan that uses sound waves to create a picture of the thyroid. It is used to look at lumps, nodules, or changes in the size and structure of the gland.
- Radioactive iodine uptake scan — a specialist scan that shows how active the thyroid gland is and how it uses iodine. Used mainly when an overactive thyroid is suspected.
- Fine-needle aspiration biopsy (FNA) — if a thyroid nodule is found, a thin needle is used to take a tiny sample of cells to check whether they are benign (harmless) or cancerous. This sounds more daunting than it is — it is usually quick and done under local anaesthetic.
- CT or MRI scans — sometimes used if a large goitre or suspected cancer needs a more detailed picture.
What to expect at your appointment
The process of getting a thyroid diagnosis is usually straightforward. Most people start with a blood test ordered by their GP (family doctor). Results are typically available within a few days. If the blood test suggests a problem, your doctor will talk you through the results and discuss next steps — this might mean a repeat test, a referral to a specialist, or additional scans. At no point should you feel rushed or confused — it is always okay to ask your doctor to explain results in plain language and to ask what happens next.
Treatment
The good news is that most thyroid disorders respond very well to treatment. The right treatment depends entirely on the type and cause of the thyroid disorder, how severe it is, and your individual health and preferences. Your doctor or specialist will work with you to find the best approach. Treatment may involve medication, a procedure, surgery, or simply careful monitoring — or a combination of these.
Self-care at home
- Take any prescribed medication exactly as directed — thyroid medications often need to be taken at a consistent time each day, and some foods or supplements can affect how well they are absorbed. Ask your doctor or pharmacist for specific guidance.
- Attend all follow-up blood test appointments — thyroid conditions need regular monitoring to make sure treatment is working and hormone levels are in a healthy range.
- Do not stop or adjust your medication without speaking to your doctor first, even if you feel well — thyroid conditions often need long-term or lifelong treatment.
- Tell all your healthcare providers (including dentists and other specialists) about your thyroid condition and any treatments you are receiving.
- If you are pregnant or planning to become pregnant, tell your thyroid specialist immediately — your hormone levels and treatment may need to be adjusted.
- Get enough sleep and manage stress where possible — fatigue and stress can worsen thyroid symptoms.
- Keep a simple symptom diary to share with your doctor at appointments — noting changes in energy, mood, weight, and any new symptoms.
Medical treatments
For an underactive thyroid (hypothyroidism), the standard and highly effective treatment is replacing the missing thyroid hormone with a synthetic version taken as a daily tablet. The dose is carefully tailored to you based on blood test results, and it may be adjusted over time. Most people find that once their hormone levels are stable, they feel much better. For an overactive thyroid (hyperthyroidism), there are several approaches. Antithyroid medicines reduce the amount of hormone the thyroid produces and are often a first-line treatment. Radioactive iodine therapy is another very effective option — it uses a carefully measured dose of radioactive iodine, swallowed as a drink or capsule, to gradually reduce the activity of the thyroid gland. It is safe and painless, though it may result in an underactive thyroid over time, which is then managed with hormone replacement. Thyroid nodules and goitres are often monitored with regular ultrasound scans if they are not causing symptoms. If they are overactive or suspicious, they may be treated with radioactive iodine or surgery. Thyroid cancer treatment depends on the type and stage but commonly includes surgery, and may also involve radioactive iodine therapy and hormone therapy. Thyroid cancer has one of the best overall survival rates of all cancers, and most people do very well with treatment.
When is surgery considered?
Surgery to remove part or all of the thyroid gland (called a thyroidectomy) may be recommended in several situations: if a thyroid nodule or goitre is large and causing symptoms such as difficulty swallowing or breathing; if a nodule is found to be cancerous or the biopsy result is uncertain; if an overactive thyroid has not responded well to other treatments; or if someone prefers surgery over long-term medication or radioactive iodine. Surgery is performed under general anaesthetic (you are fully asleep) and is a routine procedure for experienced surgical teams. If the whole thyroid is removed, you will need to take thyroid hormone replacement medication for life — but many people adapt to this very well and live full, active lives.
Living with this condition
Living with a thyroid disorder is very manageable for most people, especially once treatment is settled and hormone levels are stable. Many people notice a real improvement in how they feel within weeks to months of starting treatment. Day-to-day life with a well-managed thyroid condition often looks and feels completely normal. That said, it does require some ongoing attention — regular blood tests, consistent medication habits, and being aware of your body. There may be periods when your levels need adjusting, especially during major life changes like pregnancy, menopause, or significant illness. The key is staying connected with your healthcare team and not ignoring new or returning symptoms.
Lifestyle tips
- Stick to a consistent routine with your thyroid medication — many people find taking it at the same time every day (often first thing in the morning) makes it easier to remember.
- Avoid large amounts of certain foods that can interfere with thyroid medication absorption if your doctor has advised this — your pharmacist or dietitian can advise you personally.
- Protect yourself from extreme cold if you have an underactive thyroid — keeping warm helps reduce discomfort.
- Build regular, gentle physical activity into your routine to support energy levels, mood, and healthy weight.
- Prioritise good quality sleep — fatigue is common with thyroid conditions, and sleep is one of the most powerful recovery tools.
- Manage stress with techniques that work for you — mindfulness, gentle yoga, breathing exercises, or simply spending time doing things you enjoy.
- Be open with close family members or friends about your condition — having people who understand why you might feel tired or unwell on some days can make a real difference.
- Keep a list of your current medications and thyroid condition to share with any new healthcare provider you see.
Diet and exercise
There is no single 'thyroid diet' that cures or treats thyroid disorders — be cautious of bold claims you may see online. However, a balanced, nutritious diet supports overall health and wellbeing. Iodine is essential for thyroid health, and in most countries, a normal varied diet provides enough. Your doctor may check your iodine levels if there is a concern. Some people with thyroid conditions are advised to be mindful of very high doses of certain supplements (such as iodine or seaweed supplements) as these can interfere with thyroid function. If you have coeliac disease or gluten sensitivity alongside a thyroid condition, following a gluten-free diet may help thyroid antibody levels — but speak with your doctor before making major dietary changes. Regular exercise is generally encouraged and can help with energy, mood, and weight management. Start gently if you have been feeling unwell, and build up gradually. Activities like walking, swimming, cycling, or yoga are great starting points. Always check with your doctor before starting a new exercise programme if you have been unwell.
Mental health and emotional wellbeing
Thyroid disorders can significantly affect how you feel emotionally and mentally — and this is completely real and valid, not 'all in your head.' An underactive thyroid commonly causes low mood, depression, and difficulty thinking clearly. An overactive thyroid can cause anxiety, irritability, restlessness, and difficulty sleeping. These feelings can affect your relationships, work, and overall quality of life. It is important to tell your doctor if you are struggling emotionally, even after your hormone levels have been treated, as some people need additional support. Talking therapies, support groups, and — where needed — mental health support can all play an important role alongside your thyroid treatment. If you are ever feeling overwhelmed, hopeless, or having thoughts of harming yourself, please reach out for help immediately. You can contact a crisis support line in your country — do not face that alone.
Prevention
Most thyroid disorders — particularly those caused by autoimmune conditions or genetic factors — cannot be fully prevented. However, there are some things that can reduce risk or support thyroid health. Getting enough iodine through a balanced diet (found naturally in dairy products, fish, eggs, and fortified foods in many countries) helps prevent iodine-deficiency thyroid disorders. Avoiding unnecessary radiation exposure to the neck area where possible is also sensible. Not smoking is beneficial, as smoking is linked to a higher risk of some thyroid conditions. If you have a strong family history of thyroid disease, discussing regular thyroid screening with your doctor can help catch any problems early, before symptoms become noticeable.
Vaccines
There are no vaccines for thyroid disorders.
Screening programmes
In the UK and many other countries, newborn babies are routinely screened for congenital hypothyroidism (underactive thyroid present from birth) as part of the newborn blood spot test — a heel prick test done a few days after birth. This allows treatment to begin very early, preventing developmental problems. For adults, routine population-wide screening is not currently recommended in most countries. However, targeted screening is advised for people at higher risk — including those with a family history of thyroid disease, autoimmune conditions, or symptoms that could suggest a thyroid problem. If you are concerned, a conversation with your GP is the best starting point.
Complications
If left untreated
- Untreated underactive thyroid (hypothyroidism) can lead to a slow heart rate, high cholesterol (fatty substances building up in the blood vessels), nerve damage, infertility, and in severe cases a rare but life-threatening condition called myxoedema coma.
- Untreated overactive thyroid (hyperthyroidism) can cause dangerous heart rhythm problems (including atrial fibrillation — an irregular heartbeat), weakening of the bones (osteoporosis), and in rare severe cases a life-threatening crisis called a thyroid storm.
- Thyroid disorders during pregnancy, if unmanaged, can affect the baby's brain development and growth, and increase the risk of miscarriage or premature birth — which is why close monitoring in pregnancy is so important.
- Long-standing large goitres can press on the windpipe or food pipe, causing difficulty breathing or swallowing.
- Thyroid cancer, if not detected and treated, can spread to nearby lymph nodes (small glands that are part of the immune system) or, more rarely, to other parts of the body — though thyroid cancer is one of the most treatable cancers when caught early.
Long-term outlook
The outlook for people with thyroid disorders is genuinely positive. The vast majority of thyroid conditions — whether underactive thyroid, overactive thyroid, benign nodules, or even thyroid cancer — are very well managed with modern treatment. Many people, once their hormone levels are stable, feel completely like themselves again. Even thyroid cancer, which can sound frightening, has an excellent prognosis (likely outcome) in most cases, with very high long-term survival rates particularly for the most common types. The most important thing you can do is seek care early, stay consistent with your treatment, and keep attending your follow-up appointments. With the right support, living a full and healthy life with a thyroid condition is not just possible — it is what most people experience.
Find support
International organisations
- American Thyroid Association (ATA) — patient information resources ↗
- Thyroid Federation International ↗
- World Health Organization — Thyroid Disorders Information ↗
Local organisations
- British Thyroid Foundation (BTF) ↗ · United Kingdom
- NHS — Thyroid Disorders Overview ↗ · United Kingdom
- Thyroid Australia ↗ · Australia
- Canadian Thyroid Association ↗ · Canada
- Butterfly Thyroid Cancer Trust ↗ · United Kingdom
Helplines
External links open third-party websites. Ruqelo Health is not responsible for external content. Listing an organisation does not imply endorsement.
Always verify with your doctor
Health guidelines vary by country and region. The information in this article is based on international clinical guidelines but may not reflect the specific guidelines, medications, or practices in your country. Always discuss your health concerns with your own doctor or healthcare provider, and refer to your local national health guidelines where available.
Important notice This information is for educational purposes only. It does not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider about your specific situation. If you are experiencing a medical emergency, call your local emergency services immediately.