autolesionarse

The standard clinical and everyday term for deliberately harming one's own body — used in medical, psychological, and educational contexts about self-harm, a serious and specific topic, not a casual or figurative word.

• El especialista explicó por qué algunos adolescentes se autolesionan. — The specialist explained why some teenagers self-harm.
• Reconocer las señales de alguien que se autolesiona puede salvar vidas. — Recognizing the signs of someone who self-harms can save lives.
• La escuela ofrece apoyo psicológico a quienes se autolesionan. — The school offers psychological support to those who self-harm.

This is a sensitive clinical term, not a word to use loosely or humorously for minor self-inflicted inconveniences — treat it with the same care as its English equivalent 'self-harm.'