Adults reporting a longstanding illness are asked what the health conditions / illnesses are, and this are assigned to one of the illness categories shown in the following table.
Gofynnir i oedolion sy’n nodi bod ganddynt salwch hirdymor beth yw’r salwch / cyflyrau iechyd hyn, ac mae’r rhain yn cael eu neilltuo i un o’r categorïau salwch a ddangosir yn y tabl a ganlyn.