(CNN) -- Argentine President Cristina Fernandez de Kirchner will undergo surgery on Tuesday morning, days after doctors discovered she had a blood clot on the surface of her brain.
Over the weekend, doctors diagnosed Fernandez with a subdural hematoma and said she needed to take a month off of work.
But the president's medical plan changed after she felt a tingling sensation in her left arm on Sunday and an exam detected that she had lost some muscle strength in the limb, hospital officials said in a statement released by the presidency. That's when doctors at the Favaloro Foundation decided to operate and remove the clot, the statement said.
During Fernandez's absence, Vice President Amado Boudou is serving as Argentina's interim president.
A subdural hematoma is a blood clot on the brain's surface beneath its outer covering, called the dura. Often, in people over 60, a brain trauma can cause the blood vessels in the brain to tear and blood to clot.
In August, Fernandez, 60, suffered a cranial trauma, for which doctors conducted a brain scan and found normal results with no symptoms at the time, presidential spokesman Alfredo Scoccimarro said Saturday.
Doctors at the Buenos Aires-based Favaloro Foundation discovered the hematoma on Saturday after a neurological evaluation, he said.
According to Argentina's constitution, the vice president would assume the presidency temporarily in the president's absence. But officials have not yet announced whether that will occur.
In a televised speech Monday, Vice President Amado Boudou said the situation was similar to the time when Fernandez temporarily handed presidential powers over to him when she underwent surgery in January 2012 to remove her thyroid.
"This phase of 30 days is exactly the same," he said. "There is no question or uncertainty, no strange question. She is taking her rest, a rest that she needs, and also that she deserves. ... And the key is to keep governing. And that is what she has asked of us. And that is what you will find the whole team of the president doing, governing."
CNN's Nelson Quinones and Holly Yan contributed to this report.