Sociedade Portuguesa de Endocrinologia Frames Roughly 600,000 Undiagnosed Portuguese Thyroid Cases as the Free-Screening Push Closes Out the 21–27 May Semana Internacional da Tiroide

The Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo (SPEDM) used the Sunday news cycle of the Semana Internacional da Tiroide — running 21 to 27 May 2026 — to flag that roughly 600,000 Portuguese are likely carrying an undiagnosed thyroid disorder. The estimate, attributed to SPEDM and the affiliated Thyroid Study Group via Lusa on the morning of 25 May, sits on top of the broader population reading that an estimated 7.4 per cent of Portuguese have a thyroid disorder of some kind, with more than 5 per cent living with symptoms without a diagnosis.

The Numbers Behind the Headline

Portuguese specialists place the total population affected by thyroid disease at roughly one million across hypothyroidism, hyperthyroidism, nodular pathology and the autoimmune variants. The 600,000 figure refers specifically to the undiagnosed cohort within that total — the patients whose blood-test markers would meet a diagnostic threshold for thyroid dysfunction if tested, but who have not been tested or who have presented with non-specific symptoms a primary-care doctor has not yet linked back to the gland. The gender split is consistent across the literature: thyroid disorders affect five to eight times more women than men, and prevalence climbs with age — both factors that intersect with the underlying primary-care access patterns the new diagnostic pipeline depends on.

The Screening Programme

The Semana Internacional da Tiroide runs every May under a partnership between SPEDM, the Associação das Doenças da Tiroide (ADTI) and Merck. The 2026 edition continues the free-screening model: blood-test stations in selected hospitals and primary-care units across the country offer thyroid-stimulating hormone (TSH) readings without referral, and follow-up endocrinology consultations are scheduled where TSH values fall outside the reference range. SPEDM publishes the participating sites and screening hours on its members-facing channel; ADTI runs the consumer-facing campaign through social media and patient-association networks.

Why TSH Reading Matters

TSH is the first-line analytical marker for thyroid dysfunction because it captures the pituitary feedback loop on free thyroxine (FT4) and triiodothyronine (FT3) levels. A TSH reading above the local laboratory reference band (typically around 4.0–4.5 mIU/L for adults) flags subclinical or overt hypothyroidism; a reading below the lower band (typically 0.4 mIU/L) flags hyperthyroidism. The follow-on panel — FT4, FT3, anti-TPO antibodies and a neck ultrasound when nodules are palpated — confirms the underlying type. The screening week's specific objective is to bring the population that would not request the test through their GP into a sampling window with no cost barrier and no referral wait.

Why the Symptom Picture Is Easy to Miss

The non-specific symptom set is the central diagnostic challenge SPEDM has emphasised across multiple campaign cycles. Hypothyroidism presents through fatigue, weight gain, cold intolerance, dry skin, hair thinning, depressed mood and slowed bowel transit — each of which has a long differential diagnosis that does not start with the thyroid. Hyperthyroidism flips most of those: weight loss, heat intolerance, palpitations, anxiety, tremor, hyperdefecation. Both presentations evolve gradually and patients commonly adapt around the symptoms before raising them with their family doctor. The Sociedade Portuguesa de Endocrinologia, Diabetes e Metabolismo also runs a parallel Academia de Endocrinologia targeted at general practitioners and adjacent specialists to tighten the clinical-suspicion pipeline upstream of the consultation request.

What This Means for Expats

• If you have a family doctor in Portugal: a TSH request through your médico de família is covered by the SNS at the standard consultation co-pay. Annual TSH for women over 50 and anyone with first-degree-relative thyroid history is the broadly accepted clinical reference.
• If you do not yet have a family doctor: private endocrinology consultations across the larger Lisbon, Porto and Algarve networks typically price a first appointment at €60–€110 plus the TSH lab fee (€10–€25 retail).
• This week specifically: the SPEDM screening sites for the 2026 edition are listed via the society's own channels and the ADTI patient-association portal. Walk-ins are accepted without referral.
• Watch the symptom set: persistent fatigue, weight change without a behavioural trigger and altered cold/heat tolerance are the most-cited primary-presentation patterns. If they cluster, ask for a TSH.