Here as per your explanation, having HB 19 is some thing really good. But I need to know what about other parameters like is he having sugar ( diabetes)? Well if he is not diabetic then next is what about hypertension, cholesterol or any other medical history.? If he is healthy and this is first time some thing happening different then I suggest to check on his back pain. Is it coming from back to leg along with numbness and tingling sensation. If yes then his problem is at spinal level which is affecting the nerve coming from that particular level and so that he has pain and sensory changes at lower end of the leg where ever the nerve supplies. But if there is no symptoms of radiating pain then it could be some thing related to vascularity where his lower limb circulation might be affected. Now to have conformation on this there is physical test that is hold and squeeze his calf muscle and check about pain if he complain of pain then the test is positive showing abnormality in circulation for lower limb. How ever the conformation can be done only after dopler test for lower limb. Here just with symptoms of redness in finger tip, fatigue, pain is not enough for any diagnosis it can also be related to simple fever where you will have similar symptoms. soni suggest to take him to doctor in case the symptoms are not going on its own and get him examine properly and do needful. Take care.