Sao Paulo (CNN)Brazilian President Jair Bolsonaro has been admitted to the hospital to investigate the cause of persistent hiccups that are leading to abdominal pains, according to Brazil's Special Secretariat for Social Communication.
According to sources at the presidential palace, Bolsonaro felt abdominal pain at night and he is undergoing tests at the Armed Forces hospital in Brasilia.
The special secretariat for communication said: "On medical advice, the president will be under observation for a period of 24 to 48 hours, not necessarily in the hospital."
Bolsonaro has been complaining for more than a week of hiccups, saying it was causing him difficulties when speaking in public.
On Tuesday night he addressed the issue when talking to supporters. "Guys, I'm voiceless, guys. If I start talking too much, the hiccup bout comes back. The hiccup is back," he said.
During a social media event last Thursday, the president said that he had had hiccups "for over a week" at that point. "I may not be able to express myself properly on this live," he said.
He has suggested the condition may be related to medication he was taking due to surgery for dental implants.
According to sources, Bolsonaro is doing well. The possibility of performing surgery in the coming months to remove a hernia in the abdominal region is also being evaluated.
In January 2019, Bolsonaro underwent surgery to remove a colostomy bag fitted after he was stabbed four months earlier on the presidential campaign trail.
Last July, he contracted Covid-19, following months of downplaying the gravity of the virus.
The right-wing populist has been heavily criticized for his handling of the pandemic, which has led to more than 500,000 deaths in Brazil, one of the world's worst-hit countries.
The country has suffered from a slow vaccine rollout and staunch resistance to containment measures by Bolsonaro's government.
The president is currently facing a parliamentary inquiry led by Brazil's senate, which is investigating whether the federal government intentionally delayed the vaccine rollout in line with its herd immunity strategy.