| Rank | Clinic Name | Patient Rating | Country | Lead Doctor | experience | Techniques | Best For | Why It’s Ranked | Accreditations |
|---|---|---|---|---|---|---|---|---|---|
| #1 | 3.4 / 5 (0 reviews) | Madrid, Spain | — | — | Thyroid function tests (including T3, T4, TSH) | — | — | Joint Commission International | |
| #2 | 4.6 / 5 (16 reviews) | Madrid, Spain | — | 26,000+ treatments | Radiotherapy for lung cancer, Radiosurgery of a brain tumor | — | — | European Foundation for Quality Management, TÜV AG Сompany Research & Investing Certificate | |
| #3 | 2.5 / 5 (0 reviews) | Madrid, Spain | 36+ years | Thyroid function tests (including T3, T4, TSH) | — | — | European Foundation for Quality Management, Certification according to DIN EN ISO 9001 by TÜV NORD CERT |