The most important factor that governs your health is the health of your ascendant. Oh yes! The ascendant is single most important factor of good health! It is strong if you see following indications in one's chart:
1. Ascendant is Vargottama. It actually means that same number is written in House 1 for D1 (main chart) and the D9 (the Navmansa). For example, if your ascendant is Leo and ascendant in D9 is also Leo, then your ascendant is Vargottama and hence very strong!
2. Ascendant has benefic planets such as Jupiter, Venus, Mercury and Moon (of brighter half of month). This could be true even when the benefic is enemy to ascendant. E.g. in case of Leo ascendant Venus' presence will give good health. Also, if benefics occupy houses 5 and 9, they give good health. Also, aspect of benefics over ascendant helps a lot!
3. When ascendant lord sits in ascendant or aspects it, the ascendant grows in strength. E.g Mars putting aspect on Scorpio ascendant (owned by Mars), from Leo (in 10th).
4. Presence of Rajyogas is another thing to consider. If one has several Rajyogas associated with ascendant, then good health is assured. E.g. for Virgo ascendant, if the Lord Mercury and Venus combine together in 10th house, good health is assured.