StarchaserNancy mentioned that stress can correspond with later physical health issues, which was part of the med. astrology lore I also learnt. Stress arises whenever a situation occurs that is going to change that with which one has become (too) accustomed (conditioning of Moon and Saturn influences) and has difficulty accepting and handling. It is difficult for the individual ‘to move on’; i.e. forward and leaving the past for what it was.
As you say the 6th house is associated with physical complaints. Is it coincidence that the charts provided show this house has Aquarius on its cusp, the sign ruled traditionally by Saturn (under a Moon influence?) and in modern astrology by Uranus (under a Sun influence?)? Saturn can relate to pressure, clots, etc., Uranus with the circulatory systems of the body. They form a T-square with Mercury (communicative relating and thought), ruler Virgo Ascendant (physical constitution) and Gemini M.C Mind process of/with public life), and Mars, ruler of Aries influenced 8th house ( and Scorpio on 3rd house cusp in youth). There is also a stress- indicated 135* ( want but effort necessary) aspect to Jupiter in the 9th house (health issues!)
Mars forms a second stress- indicated 135* aspect with Pluto (ruler Scorpio in adulthood).
In western astrological thought, Sun in the chart has no bearing on the houses associated with health. Other systems indicate that as Leo is the natural ruler of the 5th house, this house is also associated with conditions of the heart irrespecitve of the sign on its cusp. Capricorn, ruler Saturn, is on the 5th house cusp.
Sun forms a separating opposition to natal Neptune in Capricorn in 5th house. This can indicate a weakness in/of spirit through Capricorn type fear (False Evidence Appearing Real) and the feelings they induce instead of freeing one’s self from their influence.
The sec. progr. Sun in 12th makes no contact with a natal planet.
S.P. Mercury in Leo in 12th house IS approaching the FIXED square with natal Jupiter (swelling, enlargements).
Could this also relate to a mental attitude making much of one’s state of health (for which Virgo has a reputation), following a worrying period 2 or so years back when it aspected natal Sun in Cancer?
S.P Venus is separating from its ‘ internally painful’ conjunction with Chiron.
S.P. Mars in Aries is separating from the square with natal Neptune’s fears and illusions, and will approach and complete its effect upon the Sun-Neptune oppositon in a few years . This could be an excellent time to take stock of internal worries, become more active and assertive in yourself, whereby physical concerns can decrease.
Hopefully the above can help towards discovering the why of physical complaints and provide answers in how change can deal with them successfully. .
With the outer planets all entering new signs bringing new concepts and attitudes towards life in general, let them work in a positive way for you. Life is too short not to take advantage of every change and turn one encounters on its path. 
