When someone dies as a result of a disease or injury, you can say that they die of the disease or injury or die from it.
You say someone dies of hunger or thirst, or dies of natural causes. Don't use "die from".
[Source: Collins COBUILD English Usage]

现在好像没区别了，我见用那个都行。

die of……是指那种生老病死。另外一个指的是死于外因，比如车祸啥的

牛津/科林斯(词霸版)
把 die of/from解释成一样了。如，to die of/from cancer.
但(natives高手)网络答疑 说
1. Die of diseases and old age and bad habits.
Die from wounds and injuries.
Die in an accident.
Die for a great cause or for the country.
.
2. Both actually work. It just depends who you are talking to. Different people will find different versions more natural. Either way, everyone will understand the point you are trying to make.
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