These are in addition to the more common symptoms such as fever, cough, cold, diarrhoea and shortness of breath, he said.
"But the symptoms that go unnoticed are fatigue and the loss of the sense of smell and taste. These are also symptoms," he said at his daily COVID-19 status update for the media, here.
Dr Noor Hisham said the officer who was found to be COVID-19 positive at a post-Cabinet meeting at the Prime Minister's Office recently did not have the more common symptoms but was suffering from fatigue.
He said the Ministry of Health conducted a screening and found the officer to be positive of the disease.
Dr Noor Hisham also said it does not mean that a person without any fever does not have symptoms of COVID-19.
"But if a person has symptoms (clearly evident or mild), he or she should not go to the office at all," he said when replying to a question from a reporter on the differences in the temperature readings of the thermometer used.
On another development, Dr Noor Hisham said the ministry will consider how to accommodate COVID-19 patients who have been discharged after 14 days but do not want to return home.
"If they do not want to return home, then we will look at how we can put them up at a hospital or at a training institute for asymptomatic people or those with mild symptoms.
"We only retain those who show symptoms on the first day and on the 14th day as well because the symptoms are due to the presence of the virus and infectivity potential or complications," he said.
Dr Noor Hisham said that if a patient has complications and needs extended treatment, the ministry will monitor and treat the patient until he or she is discharged.
He also said that the ministry will soon publish guidelines soon for its specialists and doctors on the treatment and management of patients during the 14-day incubation period.
On another matter, he said the ministry is working with the National Security Council (MKN), police and NGOs to implement the monitoring of compliance with the SOPs during leisure and exercise activities at public parks which are getting congested and where social distancing may be difficult to enforce.