Thyroid Scan

A thyroid scan evaluates the gland’s size, shape and position, detects nodules, cysts or diffuse enlargement, and shows how thyroid tissue takes up radioactive tracer—identifying “hot” (overactive) versus “cold” (underactive) areas. It helps diagnose hyperthyroidism, thyroiditis or goitre, assesses nodule function and cancer risk, and guides fine‑needle biopsy; it cannot confirm malignancy alone.

A thyroid scan is generally not painful. For nuclear medicine scans, you may get a small injection or swallow a tracer; the injection can sting briefly but the scan itself causes no pain. Ultrasound scans are painless, though slight pressure may be felt from the probe. If a biopsy (fine‑needle aspiration) is needed, that can cause brief discomfort. Ask your team what to expect.

A thyroid scan usually means a radionuclide (scintigraphy) study using radioactive iodine (I‑123 or I‑131) or technetium‑99m pertechnetate. After a tracer dose is given, a gamma camera images the gland to assess size, shape and function and to identify “hot” (overactive) or “cold” (non‑functioning) nodules. Ultrasound, CT or MRI show anatomy but not gland function.

A thyroid scan is generally safe: it uses low‑dose radioactive tracers or ultrasound (no radiation). Radiation exposure is minimal and unlikely to cause harm for most people. Pregnant or breastfeeding women should avoid radioactive scans and discuss alternatives. Allergic reactions and side effects are rare. Tell your clinician about pregnancy, recent iodine tests, or kidney issues so they can choose the safest test and dose.

Thyroid scan costs vary by country, facility and test. An ultrasound usually ranges from about $50–$500 (or ₹500–₹2,500), while nuclear medicine thyroid scans (uptake/scan) are higher, roughly $300–$1,500 (or ₹2,000–₹10,000). On public health systems these scans are often provided free when clinically referred. Exact prices depend on location, provider and insurance.

Usually you should avoid eating or drinking for a few hours before a thyroid scan, but requirements vary by scan type. You may also be asked to stop thyroid medications and avoid iodine-containing foods, supplements, or recent contrast studies for days to weeks beforehand. Follow the specific instructions given by your doctor or imaging center; contact them if you’re unsure about fasting or medication adjustments.