The 6th house — the traditional seat of health in a chart
In Vedic astrology, the sixth bhava (house) from the ascendant is traditionally read for disease, injury, daily obstacles, and the body's capacity to cope with and recover from illness. Afflictions to this house, or to its ruling planet, are traditionally read as tendencies toward particular kinds of health challenge — read as an area of attentiveness within the classical system, not a prediction or diagnosis.
Signs and body parts — the head-to-feet mapping
Classical astrology assigns each of the twelve signs a body region in sequence: Aries (head/face), Taurus (throat/neck), Gemini (arms/lungs/nervous system), Cancer (chest/stomach), Leo (heart/spine), Virgo (digestive system/intestines), Libra (kidneys/lower back), Scorpio (reproductive/excretory system), Sagittarius (hips/thighs/liver), Capricorn (knees/bones/joints), Aquarius (calves/circulatory system), and Pisces (feet/lymphatic system).
Planets and their traditional health associations
The Sun is traditionally linked to vitality, heart, and bones; the Moon to mind, fluids, and digestion; Mars to blood, muscles, and injuries; Mercury to the nervous system and skin; Jupiter to the liver, fat metabolism, and overall growth; Venus to reproductive health and kidneys; Saturn to chronic conditions, bones, and joints; and Rahu and Ketu (the lunar nodes) to unusual, hard-to-diagnose, or chronic conditions in classical texts.
Doshas and Ayurvedic astrology
Ayurvedic astrology specifically overlays the Ayurvedic dosha framework onto the planets — commonly, Sun/Mars/Ketu associated with Pitta (fire), Moon/Venus associated with Kapha (water/earth), and Saturn/Rahu/Mercury associated with Vata (air/space) — traditionally used to suggest a person's constitutional tendency alongside an Ayurvedic assessment, not to replace one.
How this is traditionally used, and its limits
Historically, medical astrology was used alongside — never instead of — the physician's direct examination; a chart might be read for general constitutional tendency or the timing of vulnerability via dasha (planetary periods), while actual diagnosis and treatment remained the domain of the Ayurvedic or other physician. That division matters just as much today: medical astrology is not a substitute for professional medical care, testing, or diagnosis of any kind. Treat it strictly as a traditional, symbolic framework — not as health information to act on.