Ketu in Vedic Astrology
Ketu is dark in complexion, smoky colour, tall and inhaling smoke. He rules maternal grand father and paternal grand mother. Malefic, religious, sectarian principles, pride, selfishness, occultism.
Diseases
He rules intestinal worms, smallpox, cholera and other epidemics. He generally causes the same diseases as Rahu.
Caste : Low caste
Direction : South West
Sex: Hermaphrodi
Malefics always tend to do harm but under certain conditions, the intensity of the mischief is tempered. Benefics on the other hand tend to do good, but some times they also become capable of doing harm.
General Significations of Ketu
Knowledge of the self, renunciation, knowledge of the mantras and tantras, secret learning, detachment, bath in holy rivers, pilgrimage, penance, hunger, vow of silence, Vedantic philosophy, disease, physician, a flag, association with hunters, fortune, suffering, luxuries, paternal grandfather, vultures, dogs, deer, cocks, pain, injury, surgical treatment, horned animals, thorn, stone, trouble from enemies.
In Medical Astrology
Chronic disease, tuberculosis, viral diseases, eruptive fevers, epidemics, worm infestations, non-healing wounds, mental instability, diseases causing diagnostic confusion.