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Hyperthyroidism is an overactive thyroid that makes too much thyroid hormone. Treatment depends on the cause and may include antithyroid medication, radioactive iodine or surgery. The cause, your symptoms, eye health and pregnancy plans all help determine the best option. A beta-blocker can ease symptoms such as a rapid heartbeat and shaky hands while the main treatment takes effect. Endocare treats hyperthyroidism at our clinic in Dubai Healthcare City.
- The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) names Graves’ disease, an autoimmune condition, as the most common cause of hyperthyroidism.
- A suppressed TSH alongside a raised free T4 or free T3 indicates overt hyperthyroidism, and your endocrinologist will look for the cause before discussing treatment.
- During the first three months of pregnancy, NIDDK notes that propylthiouracil is often the antithyroid medication used.
- If you develop a fever or a severe sore throat on antithyroid medication, the American Thyroid Association advises seeking medical care immediately.
- NIDDK states that almost all people treated with radioactive iodine go on to need a daily thyroid hormone medication.
- Your endocrinologist will refer you for radioactive iodine treatment or thyroid surgery where either is indicated, as Endocare does not perform them.
01 Introduction
An overactive thyroid produces more thyroid hormone than the body needs, which can speed up many of the body’s functions. The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) reports that around 1 out of 100 Americans aged 12 and older have hyperthyroidism. Our endocrinologists diagnose and treat hyperthyroidism as part of their care for thyroid conditions at our Dubai clinic.
02 What hyperthyroidism is
Thyroid hormone helps regulate the heart rate, the bowel, the nervous system and the rate at which the body uses energy. An excess of thyroid hormone can speed these functions up. The clinical term for this state is thyrotoxicosis. Hyperthyroidism is the form of thyrotoxicosis in which the thyroid gland itself produces too much hormone.
03 The symptoms of an overactive thyroid
NIDDK lists the symptoms of hyperthyroidism as follows.
- Weight loss despite an increased appetite
- A rapid or irregular heartbeat
- Nervousness, irritability and trouble sleeping
- Fatigue
- Tremor and muscle weakness
- Sweating, or difficulty tolerating heat
- Frequent bowel movements
- Goitre, meaning a visible enlargement of the gland
NIDDK notes that older adults may have different symptoms, such as a loss of appetite or withdrawal from people. In older adults, hyperthyroidism is sometimes mistaken for depression or dementia.
04 What causes an overactive thyroid
NIDDK lists the causes of hyperthyroidism as including the following.
- Graves’ disease, an autoimmune condition and the most common cause
- Overactive thyroid nodules
- Thyroiditis, meaning inflammation of the thyroid gland
- Excessive iodine consumption
- Excessive thyroid hormone medicine
- Rarely, a noncancerous pituitary tumour
Your endocrinologist will also assess any thyroid nodules, including a nodule that produces hormone on its own.
05 How hyperthyroidism is diagnosed
NIDDK states that symptoms alone are not enough to diagnose hyperthyroidism. Your endocrinologist will read TSH alongside free T4 and free T3.
What your thyroid function results mean together
| Result pattern | What it indicates | What your endocrinologist will do |
|---|---|---|
| Low TSH with a raised free T4 or free T3 | Overt hyperthyroidism | Identify the cause, then choose a treatment route with you |
| Low TSH with a normal free T4 and free T3 | Subclinical hyperthyroidism | Repeat the test and look for a cause before deciding whether to treat |
| Normal TSH with a normal free T4 | Normal thyroid function | Look elsewhere for the cause of your symptoms |
| Raised TSH with a raised free T4 | An uncommon pattern that can point to the pituitary gland | Investigate further before starting treatment |
These definitions follow NIDDK and the UK National Institute for Health and Care Excellence (NICE). Laboratories publish their own reference ranges, so your endocrinologist reads your result against your own laboratory’s range.
Finding the cause
The treatment route depends on the cause, so identifying it comes first. Your endocrinologist may arrange a thyroid antibody test, because a positive thyroid-stimulating immunoglobulin result points to Graves’ disease. An ultrasound can describe the gland and any nodule within it. Where the cause remains unclear, a radioiodine uptake scan can show which part of the gland is overactive.
06 How an overactive thyroid is treated
Treatment aims to control the symptoms and to bring thyroid hormone levels back into the reference range. A beta-blocker treats the symptoms, while antithyroid medication, radioactive iodine and surgery treat the thyroid itself. Thyroiditis, in which stored hormone leaks from an inflamed gland, is generally not treated with antithyroid medication.
Beta-blockers, which treat the symptoms rather than the cause
NIDDK states that beta-blockers can make you feel better within hours. It also states that they do not stop thyroid hormone production. The American Thyroid Association describes them as medications that help control symptoms such as a rapid heart rate, shakiness and nervousness. Your endocrinologist may recommend a beta-blocker while the main treatment takes effect.
Antithyroid medication
Antithyroid medication reduces how much hormone the thyroid produces. NIDDK states that methimazole is the antithyroid medication used most often. NIDDK gives an average total treatment time of around one to two years, although treatment can continue for many years. Your endocrinologist will review your levels throughout.
NIDDK lists the possible side effects of antithyroid medication as allergic reactions such as rashes and itching, a fall in the number of white blood cells, and, in rare cases, liver failure. The American Thyroid Association gives patients the following safety instructions.
- If you develop a fever or a severe sore throat, seek medical care immediately for a complete blood count, and take no further doses until your doctor clears you to restart
- Contact your doctor immediately if you develop a red skin rash or hives
- Contact your doctor immediately if you notice yellowing of your eyes or skin, itching, or dark urine, because these can indicate liver injury
The American Thyroid Association describes the fall in white blood cells, called agranulocytosis, as rare and potentially life-threatening. We recommend keeping these instructions somewhere you can find them for as long as you are taking the medication.
Radioactive iodine
Radioactive iodine slowly destroys the cells of the thyroid gland that produce thyroid hormone. NIDDK states that almost everyone who receives radioactive iodine later develops hypothyroidism. It also states that hypothyroidism is easier to treat than hyperthyroidism, using a daily thyroid hormone medication. Your endocrinologist will explain this before you choose this route. A nuclear medicine service gives the treatment. Your endocrinologist will refer you where it is indicated.
Surgery
Surgery removes part or most of the thyroid gland. The American Thyroid Association states that patients who undergo complete removal of the thyroid will require lifelong thyroid hormone supplementation. After partial removal, some patients may also need thyroid hormone. Endocare does not perform thyroid surgery. Where an operation is indicated, your endocrinologist will refer you to a surgeon. Our endocrinologists can then manage the hormone replacement after surgery.
The three treatment routes compared
The table below sets the three routes side by side. Suitability is a clinical decision your endocrinologist makes with you.
| Option | How it works | Route | What follows treatment |
|---|---|---|---|
| Antithyroid medication | Reduces how much hormone the thyroid produces | Tablet, taken daily | An average total treatment time of around one to two years. Remission is possible for some patients, and the condition can return in others |
| Radioactive iodine | Slowly destroys the cells that produce thyroid hormone | Taken by mouth, given by a nuclear medicine service | Almost everyone develops an underactive thyroid afterwards and needs daily thyroid hormone medication |
| Surgery | Removes part or most of the gland | An operation, performed by a surgeon | Lifelong replacement after complete removal, and possibly after partial removal |
The table is drawn from NIDDK and the American Thyroid Association. A beta-blocker can be used alongside any of the three, because it controls symptoms without treating the thyroid itself.
07 Why many patients take levothyroxine afterwards
Radioactive iodine and complete removal of the thyroid lead to an underactive thyroid in almost every case. An underactive thyroid can also develop after antithyroid medication in some patients. Treatment for an underactive thyroid uses a once-daily levothyroxine tablet, with blood tests until the dose is stable.
08 How often you are re-tested during treatment
For people taking antithyroid medication, the NICE thyroid disease guideline advises considering tests of TSH, free T4 and free T3 every six weeks until TSH is within the reference range. After that, NICE advises considering a TSH test every three months until the antithyroid medication is stopped. After radioactive iodine, NICE advises considering the same three tests every six weeks for the first six months, until TSH is within the reference range.
09 What happens if an overactive thyroid is left untreated
NIDDK lists the complications of untreated hyperthyroidism as including an irregular heartbeat that can lead to blood clots, stroke and heart failure. Its list also includes Graves’ eye disease, thinning bones, osteoporosis, muscle problems, and menstrual and fertility problems. These risks are one reason your endocrinologist may recommend treatment even when you feel only mildly unwell.
10 The symptoms that need urgent attention
Care for an overactive thyroid generally takes place at planned appointments. Some symptoms need urgent attention.
- Call an ambulance on 998 if you develop chest pain, severe breathlessness, or collapse
- Call an ambulance on 998 if you develop a high fever together with confusion or agitation
- Seek medical advice immediately if your heart becomes fast and irregular, or if a racing heartbeat does not settle
- Seek medical advice immediately if you develop a fever or a severe sore throat while taking antithyroid medication
11 An overactive thyroid in pregnancy
Your endocrinologist will manage an overactive thyroid differently in pregnancy, because the choice of antithyroid medication can change. NIDDK states that propylthiouracil is often used for women during the first three months of pregnancy. It also states that mild hyperthyroidism during pregnancy is often not a problem. Severe hyperthyroidism, when untreated, can affect both mother and baby. We recommend telling your endocrinologist as soon as you are pregnant or planning a pregnancy.
12 An overactive thyroid and body weight
Weight loss is a common symptom of an overactive thyroid. The American Thyroid Association states that weight lost because of excess thyroid hormone is reversed when thyroid levels return to normal. It also notes that some patients may gain more weight than they lost, because they may have become used to eating more. Body composition analysis at your appointments helps your endocrinologist follow these changes. Our endocrinologists can advise on thyroid disorders and body weight once your levels are stable.
13 An overactive thyroid in the UAE
Published local data on an overactive thyroid is limited. The largest recent Dubai study, published in BMC Public Health in 2025, measured hypothyroidism in 77,758 adults tested at Dubai Health primary healthcare centres. It does not report how common an overactive thyroid is in the UAE.
NIDDK lists too much iodine among the causes of hyperthyroidism. It also states that seaweed and seaweed-based supplements contain a lot of iodine. We recommend telling your endocrinologist about every supplement you take, because a source of excess iodine can be stopped.
14 What your care at Endocare involves
Specialist thyroid care at Endocare begins with a full medical assessment. Your endocrinologist will review your symptoms, your medical history and your thyroid blood tests, examine your neck, and explain what your results mean. Where possible, your first appointment takes place in person at Endocare’s Dubai clinic, as the physical examination and body composition analysis cannot be completed remotely.
An overactive thyroid can change body composition as well as weight, because thyroid hormone affects how the body uses energy. At Endocare, body composition analysis is included free of charge at every consultation. Body composition analysis estimates body fat, muscle mass and body water. Repeated measurements help your endocrinologist understand how your body is changing beyond the number on the scale.
Follow-up appointments can be held in person at the clinic or online. Your endocrinologist will arrange the blood tests your treatment calls for.
15 FAQ
What is the most effective treatment for hyperthyroidism?
No single answer fits every patient, because the three routes control the thyroid in different ways and leave different outcomes. Your endocrinologist will weigh the cause, the size of your gland, your age, whether you are planning a pregnancy, the health of your eyes and your own preference.
Is hyperthyroidism serious?
It is treatable, and it can be serious if left untreated. The complications NIDDK lists include heart rhythm problems that can lead to a stroke, as well as thinning bones.
Will I end up with an underactive thyroid?
After radioactive iodine, very likely, as NIDDK states that almost everyone treated this way later develops hypothyroidism. After complete removal of the thyroid, the American Thyroid Association states that lifelong thyroid hormone supplementation is required. After antithyroid medication, some patients stay well without further treatment, while others need radioactive iodine or surgery.
Can an overactive thyroid come back after treatment?
After a course of antithyroid medication, it can return in some patients. Your endocrinologist will continue testing you after the course ends for that reason. After radioactive iodine or complete removal of the thyroid, the gland is unlikely to overproduce again. Monitoring then focuses on your replacement dose.
Our Dubai clinic is located in Building 27, Block B, Unit 504 B, Dubai Healthcare City. Opening hours are Sunday 10:00-20:00, Monday 08:30-18:30, and Tuesday to Thursday 10:00-20:00. The clinic is closed on Fridays. Free parking is available in the building and on the surrounding streets. For patients using public transport, Dubai Healthcare City Metro Station on the Green Line is the nearest stop.
Bring your most recent thyroid blood tests and any previous scans to your appointment.
To book a consultation, call our Dubai clinic on +971 4 285 3885.
Book Your Consultation
- Specialist consultation
- Personalized Coaching
- Body Composition Analysis