Former Brazilian president Luiz Inacio Lula da Silva was recovering well Monday from the pneumonia with which he was admitted into a Sao Paulo hospital a day earlier, according to dpa. Lula had a good night and had no more bouts of fever, David Uip, one of his doctors, told Brazilian TV channel GloboNews. The doctor said that Lula was undergoing tests at the Syrian-Lebanese Hospital to determine the cause of his pneumonia, which was likely to keep him in hospital until the weekend. On Sunday Uip had noted that Lula, 66, needed careful attention as he had only just ended an aggressive chemotherapy and radiotherapy treatment to fight a cancer of the larynx he was diagnosed with in October. "In a patient Lula's age, who has just undergone aggressive treatment, anything is serious. A flu can be serious," Uip said. According to his aides, Lula - who left power on January 1, 2011 - has lost weight and has trouble swallowing. In recent days he had a fever, which led him to be admitted into hospital. Paulo Hoff, another of Lula's doctors, stressed however that such problems were common. "He is in the recovery phase. It's normal to lose weight, and the immune system is affected," he said.