Quick answer. Thyroid disorders include hypothyroidism (an underactive thyroid), hyperthyroidism (an overactive thyroid, most often from Graves’ disease) and thyroid nodules. They are diagnosed mainly with blood tests for TSH and free T4 (FT4), sometimes with antibodies and an ultrasound. See a doctor or endocrinologist if you have persistent symptoms or an abnormal result. This guide is general information, not medical advice.
The thyroid is a small gland in the neck that controls your metabolism. When it produces too little or too much hormone, it can affect energy, weight, heart rate, mood and many other functions. Thyroid disorders are common and very treatable once diagnosed. In Singapore, diagnosis usually starts with a simple blood test (TSH and FT4), and care may be provided by a GP, polyclinic or an endocrinologist. This guide outlines the main thyroid conditions, the tests involved and when specialist input helps.
At a glance
| Condition | TSH | Free T4 (FT4) |
|---|---|---|
| Normal thyroid | Normal | Normal |
| Hypothyroidism (underactive) | High | Low |
| Subclinical hypothyroidism | High | Normal |
| Hyperthyroidism (overactive) | Low | High |
| Subclinical hyperthyroidism | Low | Normal |
| Graves' disease | Low | High (often with positive TRAb antibodies) |
Hypothyroidism (underactive thyroid)
Hypothyroidism means the thyroid does not make enough hormone, slowing metabolism. Common symptoms include tiredness, weight gain, cold intolerance, dry skin, constipation and low mood.
- On blood tests, TSH is typically high while FT4 is low.
- It is most often treated with a daily oral tablet of levothyroxine (synthetic T4), with dose adjusted by blood tests over time.
- Treatment is usually long-term and monitored periodically.
Dosing must be set by your doctor.
Hyperthyroidism and Graves' disease
Hyperthyroidism means too much thyroid hormone, speeding up metabolism. Symptoms can include palpitations, weight loss, heat intolerance, tremor, anxiety and difficulty sleeping. Graves’ disease, an autoimmune condition where antibodies stimulate the thyroid, is the most common cause.
- On blood tests, TSH is typically low while FT4 (and often FT3) is high.
- TSH receptor antibodies (TRAb) help confirm Graves’ disease.
- Treatment options include anti-thyroid medication, radioactive iodine or surgery, depending on the cause and your situation.
Treatment choice should be discussed with an endocrinologist.
Thyroid nodules
Thyroid nodules are lumps within the thyroid and are very common. Most are benign, but some need evaluation to rule out cancer.
- An ultrasound assesses the size and features of a nodule.
- A fine-needle aspiration cytology (FNAC) biopsy may be done for suspicious nodules.
- Thyroid function tests check whether a nodule is affecting hormone levels.
Most nodules are monitored rather than removed, but follow your doctor’s advice.
Tests: TSH, FT4 and beyond
A basic thyroid function test measures TSH and FT4.
- TSH is the most sensitive first-line screening test; it rises when the thyroid is underactive and falls when overactive.
- FT4 (free T4) reflects the active hormone available to your tissues.
- FT3, TRAb and other antibodies may be added depending on results.
- Ultrasound is used to assess nodules or an enlarged thyroid (goitre).
When to see an endocrinologist
Many thyroid problems can be started by a GP or polyclinic. Consider an endocrinologist if you have hyperthyroidism or Graves’ disease, a nodule needing assessment, thyroid problems in pregnancy, difficulty stabilising hormone levels, or eye symptoms linked to Graves’ disease. Your GP can refer you, and a referral may help with subsidies.
Who is more at risk
Thyroid disorders are more common in women and can run in families. Other risk factors include other autoimmune conditions and certain medications. If you have persistent symptoms or a family history, ask your doctor whether a TSH test is appropriate.
What to expect when you are tested
Diagnosis usually begins with a simple blood test for TSH and free T4, which can be arranged by a GP or polyclinic and does not normally require fasting. If results are abnormal, your doctor may add further blood tests such as FT3 or thyroid antibodies, or arrange an ultrasound to look at a nodule or an enlarged thyroid. If you start treatment, expect repeat blood tests over the following weeks and months while the dose is adjusted, then periodic monitoring once your levels are stable.
Living with a thyroid condition
Most thyroid conditions are managed well with medication and regular review. If you take levothyroxine for an underactive thyroid, take it consistently as directed, usually on an empty stomach, and tell your doctor before stopping or changing brands. Do not adjust the dose yourself based on how you feel; let blood tests guide changes. Report new or worsening symptoms such as palpitations, marked weight change, or eye discomfort, which can occur with Graves’ disease.
Thyroid disorders in pregnancy
Thyroid hormone levels matter a great deal in pregnancy, for both mother and baby. If you have a known thyroid condition and are pregnant or planning pregnancy, tell your doctor early, as medication and target levels often need adjusting and closer monitoring. New thyroid problems can also appear during or after pregnancy, so persistent symptoms should be checked rather than dismissed as normal tiredness.
Costs and subsidies in Singapore
Initial thyroid testing and stable management can often be handled at a GP or polyclinic, with subsidised rates for eligible residents and referral to an endocrinologist when needed. From January 2027, MOH plans to include hypothyroidism and hyperthyroidism in the Chronic Disease Management Programme, which will let eligible patients use MediSave towards approved outpatient care and access CHAS subsidies for ongoing thyroid treatment. Ask your doctor what financing applies to your situation.
Common questions
Are thyroid problems serious?
Most are very treatable once diagnosed, but untreated thyroid disorders can affect the heart, mood, weight and, in pregnancy, the baby. Persistent symptoms or an abnormal result deserve follow-up.
Do I need to see an endocrinologist?
Many thyroid problems can be started by a GP or polyclinic. Specialist input is helpful for hyperthyroidism or Graves’ disease, nodules needing assessment, thyroid problems in pregnancy, hard-to-stabilise levels, or eye symptoms.
Will I need treatment for life?
Sometimes. Hypothyroidism often needs long-term daily medication, while some forms of hyperthyroidism are treated for a defined period. Your doctor will explain what to expect for your specific diagnosis.
Related guides
- Best Endocrinology & Diabetes Clinics in Singapore — our editorial shortlist
- endocrinology & diabetes clinics directory
- Type 2 diabetes care
- Prediabetes prevention
- Diet and monitoring
Sources
- SingHealth – Hypothyroidism
- SingHealth – Hyperthyroidism
- National University Hospital – Thyroid
- HealthXchange – Thyroid Disorders Q&A
Related conditions & guides
Related conditions and guides you may find useful:
Part of our Diabetes & hormones guides · Browse all health topics