Aguascalientes screens 30,000 people for hypothyroidism in record-breaking health exam

Published 30 June 2026
The pharma professionals onstage at the hypothyroidism event in Aguascalientes

As the crowd swarmed the streets of Aguascalientes, Mexico for the San Marcos Fair this spring, a booth sponsored by the Health Office of Aguascalientes and pharmaceutical company Merck was taking a record-breaking approach to protecting the livelihoods of the people in their country.

In an effort to raise awareness for hypothyroidism – a common underactive thyroid condition – the two groups united at the fair to arrange quick and easy online risk screenings for the public, while they were enjoying the music and festivities. 

With this inviting strategy, they were able to test a record-breaking 31,559 people during the celebrations between 26 April and 3 May, officially taking the title for the most online hypothyroidism screening forms completed in one month.

Testing a finger for hypothyroidism

It all started two years ago, when Merck Pharmaceuticals made a similar record attempt in Germany for the most online pre-diabetes/diabetes screening forms completed in one week, drawing a total of 47,269 responses from their campaign in Darmstadt. 

And this time around, they were eager to repeat their success in Mexico, where this silent disease is particularly underresearched. 

La Feria de San Marcos is by far Aguascalientes’ largest festival, and they were determined to make a difference in the health of the local population during the month-long entertainment.

“Reaffirming our commitment to society through Guinness World Records is the best thing we can do,” said the organizers.

Hypothyroidism occurs when the thyroid gland doesn’t produce enough hormones – and though symptoms may be mild at first, without treatment it can progress to other health concerns such as high cholesterol and heart conditions.

Older people, pregnant women, and those with cardiovascular diseases are particularly affected, so doctors encourage screening if you present with some of the following symptoms, including: fatigue, weight gain, feeling cold, dry skin, hair loss, and brain fog.

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Since the symptoms can be so general, hypothyroidism often goes undetected – so Merck and the Health Office of Aguascalientes were eager to provide screening for the largest number of people in the region. 

And using the Guinness World Records platform, they could send a message that will be heard in Mexico and around the world, raising awareness about this silent disease and encouraging early treatment.

In all, the groups were able to gather data from 25,800 women (76.7%) and 7,839 men (23.3%), providing valuable research into the study of the condition in Latin America, while providing life-changing information to those that may be impacted by the results.

“In this work, we are fortunate and blessed to always be learning something new, and to learn something that can help you or a friend with your health is truly priceless,” said Guinness World Records Adjudicator Alfredo Arista, who verified the results.

So congratulations to Merck and Aguascalientes for this incredible attempt – you are Officially Amazing!