Sudden cardiac death is the most common cause of sudden death in this group of people (young and healthy in appearance). Specifically, the possible reasons are:
There is cardiac conduction system preexcitation syndrome, or ventricular tachycardia caused by various other reasons (subjective feeling of palpitation, palpitation, oppression, etc.). ). During the attack of ventricular tachycardia, the pumping function of the heart is completely lost, leading to death due to hypoxia. Ventricular tachycardia may have existed for a long time, but I didn't care about my family or pay attention to it.
After reading your description, it is obvious that your friend gets up early and goes to bed late, eating irregularly and living very tired. If he unfortunately has a pre-excitation bypass, such fatigue can easily lead to pre-excitation, thus inducing sudden death. In addition, frequent severe ventricular premature beats may also lead to death, and the inducement is often related to fatigue, but this possibility is relatively small in young people.
If he catches a cold recently, it may lead to myocarditis. When he has myocarditis, his heart function is very fragile and he needs strict rest. Since it seems that he didn't have enough rest, myocarditis may also be an explanation for his sudden death.
I am not an experienced doctor. I hope it helps!