Does anoxia leading to hie happen because of a disease?

More event than ill. Hypoxic ischemic encephalopathy is by definition caused by lack of blood flow(&o2) resulting in damage to the brain. Consider a sudden loss of blood presure(bp) in a pregnant mom where blood doesn't flow thru the placenta or a baby whose unstable BP slows blood flow thru the brain.Either prevents nutrients from getting to the brain & injury occurs.An illness may cause a drop BP & trigger process.
HIE. Any disease that prevents enough oxygen and blood to get to the brain for a significant period of time (several minutes) without treatment leads to hypoxic-ischemic encephalopathy (hie). This could be cardiac arrest from any disease or cause, carbon monoxide poisoning or other causes.