If someone has a chronic illness, are their sins constantly forgiven?

The Prophet said in Sahih Bukhari that even if a person has the prick of a thorn, that small scratch, there is an expiation for your sins. So every time you go through a difficulty, pain, a hard situation, Allah is expiating your sins for you. And whether that be an acute illness or that be an ongoing chronic illness, see it as a form of Allah expiating your sins for you.