This was a Q passed on to me by an astrology student to whom it was asked. It is worth noting that the native asking the Q has not said what the problem is, only that he is very ill.
The chart and significators are as follows:
The prime house of illness is the 6th. The 6th CSL is Saturn. Saturn is posited in the star of Mercury. Saturn is in the 2nd cusp in Scorpio and Mercury is in the 7th cusp in Aries. Both Scorpio and Aries are signs owned by Mars.
Due to the toughness associated with Saturn, Saturn is considered to govern bones in the human body. Mercury is the messenger and thus considered to be in charge of nerves as nerves are the messaging centers in our body.
Putting bone and nerves together, the first thing that came in mind is the backbone or spinal cord. I estimated that the native has some problem with his backbone. As Saturn is posited in Mercury it suggests that there may be multiple problems, i.e. in multiple places or multiple vertebrae. The presence of Mercury also suggests that the doctor must be careful in his diagnosis, maybe seek a colleagues opinion. Given that Mars is closely associated with both 6th CSL and 6th CSL's star, there may be an issue with muscles as well.
Saturn is posited in Scorpio. Scorpio sign governs the lower back, reproductive organs region etc. But it is also in the 2nd house which is closer to the neck region.
Mercury is posited in Aries which is the head region but in the 7th house which is again lower back, closer to reproductive organs.
Notably, Saturn strongly signifies (at starlord level) the houses 7 9 12, while Mercury signifies 7 11. The common house here is 7th. So I decided to go with lower back as the diagnosis.
Now what about recovery, is it possible? For that the 6th CSL must signify either of 1/5/11 cusps. Saturn is signifying the 5th cusp through its ownership. So recovery is possible.
When? Full recovery happens in a Dasha that signifies BOTH 5 and 11, AND a Bhukti that signifies BOTH 5 and 11. If only one is signified then only temporary relief is possible.
Current Dasha and Bhukti lord is Mercury. Mercury is signifying only 11, so relief is possible in this Dasha, but complete cure is not. There may be occasional recurrences of this illness from time to time.
5th cusp is the prime house of cure. The 5th CSL is Venus, so homeopathy may help. Venus is in the star of Jupiter so yoga will definitely help a lot. Venus is also signifying the 8th house suggesting that some surgical intervention may be needed as well.
The current Antara is of Sun which is signifying the 8th house, suggesting that the native is currently in intense pain. Sun Antara will go on till 12th May after which Moon starts. Moon does not have 8 and then the pain will lessen. Moon also has 12th cusp represented, so the Native may be shifted to a hospital.
Interestingly, as I compose this note I received a message from the student saying that the native has confirmed his problem and indeed it is in his back. The exact issue is the L6 joint, so lower back! As predicted!!
So for location, should one look at sign in which the 6th CSL is posited and the house in which the 6th CSL's star is posited? A point worth keeping in mind and testing going forward.
Just to give the readers a better perspective, I took a spinal diagram off a net search (I do not own this pic) to show just where exactly the L6 lies:
Another point worth testing is that both Saturn and Mercury were both at 22-22 degrees of their respective signs, suggesting that the issue was in 'lower' region, but not the 'lowest' region? I dont know, but will keep this in mind when a similar Q comes up next.
P:S: As far as the suddenness of the illness is concerned the only explanation I can see is that DB lord being aspected by Rahu's 9th drusthi almost to the degree.