On Anger, Book 2, Section 36 — In Plain English

Seneca — The Senator

We should think about how anger itself has hurt so many people. Some get so furious that they burst their blood vessels. Others strain their voices so hard they vomit blood. Some damage their eyesight by forcing too much blood into their eyes. They get sick when the anger finally passes. Nothing leads to madness faster than anger. Many people have stayed trapped in permanent rage. Once they lose their minds, they never get them back. Ajax went mad from anger, and his madness drove him to kill himself. People wild with rage call on heaven to kill their children, to make them poor, to destroy their homes. Yet they swear they're not angry or crazy.

Seneca — The Senator Original

We ought rather to consider, how many men anger itself has injured. Some in their excessive heat have burst their veins; some by straining their voices beyond their strength have vomited blood, or have injured their sight by too violently injecting humours into their eyes, and have fallen sick when the fit passed off. No way leads more swiftly to madness: many have, consequently, remained always in the frenzy of anger, and, having once lost their reason, have never recovered it. Ajax was driven mad by anger, and driven to suicide by madness. Men, frantic with rage, call upon heaven to slay their children, to reduce themselves to poverty, and to ruin their houses, and yet declare that they are not either angry or insane.