The classical source

Charaka Samhita, Sutrasthana 8 documents Sadvritta alongside Ahara and Nidra as a pillar of health. The chapter documents Sadvritta as practices that preserve Manas (mind), Indriyas (sense organs), and social channels. The classical logic: Manas is the governing sense organ. When disturbed by social conflict or habitual wrong conduct, the disturbance propagates through all channels into the body.

Charaka Samhita, Sutrasthana 8.18
Sadbhih saha viharena sadbhih saha vicarayet / Sadachar nishevanam cha -- Move with good people, think with good people, and habitually practise good conduct. These constitute Sadvritta -- and one who maintains them is rarely afflicted by disease of the mind or body.

The documented practices

Social

Respect elders and teachers

Documented as directly health-preserving: chronic conflict with authority figures produces sustained Rajas and Vata aggravation through the stress response.

Speech

Speak truthfully and gently

Habitual lying and harsh speech produce Prajna Aparadha (intellectual error) -- the first cause of all disease in the classical system.

Body

Maintain cleanliness

Snanam, Danta Dhavana, and Sharirashauchya as daily Sadvritta -- maintaining the Srotas near the body's surface in a clear, open state.

Conduct

Avoid cruelty and harm

Ahimsa as health practice -- habitual violence and cruelty produce Tamas and Rajas accumulation that disrupts Manas.

Intellect

Study and practice right knowledge

Svadhyaya (self-study) and Jnana acquisition maintain Sattva and prevent the Tamasic dullness documented as a direct cause of disease.

Emotions

Cultivate equanimity

Grief, fear, anger, and excessive desire when habitual produce direct Dosha aggravation. Equanimity -- not suppression but capacity to experience emotion without being governed by it -- is a clinical health practice.

Sadvritta and modern lifestyle medicine
The six Sadvritta categories map precisely to psychosocial health determinants in modern evidence-based medicine: social connectedness, honesty and self-congruence, hygiene, compassion, cognitive engagement, and emotional regulation. The classical documentation of these as direct health practices anticipates modern psychoneuroimmunology.