Brief Answer:
Needs health assessment & advise by an expert.

Detailed Answer:
Hi XXXXXXX XXXX,
Thanks for asking the query under health care magic. I have read it & understand your concern.
* There are various causes which can lead to severe pain in groin (-which may not show in routine blood examination) out of which I think following are the possibilities in his case .
-Hip joint problems ( inflammation of tendons,ligaments/ bursitis / arthritis )
- Sciatica/ Pyriformis syndrome/ Pinched nerve at spinal level
- Inguinal hernia/ Hodgkin's lymphoma ( here pain is along with swelling/ lump in the part )
-Kidney stones
- some testicular problems.
* Though his loss of weight can be simply due to excruciating pain & following stress , it can be their due to ( Tuberculosis/ hodgkin's lymphoma/ AIDs)THese conditions need to be excluded by an expert.
* It's good that his blood work is normal. still looking at the symptoms he needs a good physical examination & needful specific investigations to pin point
the diagnosis followed by specific treatment .
From this point of view, he needs an expert Physician's consultation who would after needful examination & investigations start his own treatment OR refer him to an orthopedic surgeon as per need.
Home care-
* Any person with this grade of pain & trouble is bound to be irritable & moody. Please try to bear with him to co operate & boost him up psychologically as you try to seek specific guidance from expert.
- Let him have bed rest & not try to move the leg- till he sees a doctor.
- Continue with easily digestible nourishing food./ Drink plenty of water
- Give him NSAID over the counter ( like Ibuprofen 400 to 600 as per his body weight & health ) along with Ranitidine 300 pill after his major meals 12 hourly ( twice a day), for only couple of days till you can meet an expert.
You can add sleeping pill as per your doctor- as per need.
- I hope this answers your query. Any follow up query is welcome.
Thanks.

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