The sixth house is associated with daily routines and your bread-and-butter work. Traditional astrology has this as the house of bad fortune and Mars finds its ‘joy’ (if you can call it that!) here. The sixth house is indeed problematic and it makes sense that it is associated with disease and slavery. However, I personally like to think of the sixth as the house of healing and service-to-others after breaking the bonds of abuse. The co-significator of the 6th house is Virgo.
“It concerneth men and maid-servants, galley slaves, hogs, sheep, goats, hares.. all manner of lesser cattle, and profit and loss got thereby; sickness, its quality and cause, principal humour offending, curable or not curable, whether the disease be short or long; day-labourers, tenants, farmers, shepherds…and it signifieth uncles, or the father’s brothers and sisters.
It ruleth the inferior part of the belly, and intestines even……to the arse: this house is a feminine and cadent house, unfortunate, as having no aspect to the Ascendant. Of colours, black colour. Mars rejoyceth in this house, but his cosignificator is of the Signs Virgo, of planets Mercury; we usually find that Mars and Venus in conjunction in this house, are arguments of a good Physician.”William Lilly