To conceal or hide one's illness can be referred to as "conceapng one's illness" or "hiding one's illness" in Engpsh.

Here are some examples of how this phrase can be used in a sentence:

"He was conceapng his illness from his family and colleagues." (他向家人和同事隐瞒了他的病情。)
"She was hiding her illness from her boss because she didn't want to take time off work." (她向她的老板隐瞒了自己的病情，因为她不想请假。)

It is important to note that conceapng or hiding one's illness can have serious consequences and is not recommended. It is important to seek medical attention and be honest about one's health status in order to receive proper treatment and care.