The first signs of this are visible in the urine and are as follows: if the urine is at first thick, and then begins to turn into liquid and lighten due to the retention of turbidity in the kidneys, this suggests the formation of a stone; however, the patient often first produces liquid urine; the fact that the urine is thick at the beginning of the disease rather indicates a healthy state of kidney strength and the width of the channel. Sometimes there is a copious sediment, similar to the sediment observed in diseases of the upper parts of the liver. The lighter the urine, the longer it remains light and the less sediment there is, the more definite an indication of the greater hardness of the stone. It is said that if a healthy person, especially an old man, urinates black urine, with or without pain, this indicates the formation of a stone in his bladder; in all these cases the conclusion becomes perfect if you find a sediment in the form of sand and this sand is reddish or yellowish.
It is reinforced if the patient feels heaviness and pain in the lumbar region, as if something is locked there and when moving it makes itself felt near the lower back. This sensation rather indicates the significant strength of the kidneys and the width of the passages. The most severe pain due to a kidney stone occurs at the beginning of its inception, when it tears the tissue to establish itself there, as well as when the stone moves and passes through the channels, especially through the channel into the bladder; sometimes it hurts as it moves in the bubble. And when the stone has already formed and is at rest, and the patient is also motionless, then in the absence of a large overflow, pressing and moving the stone, only a feeling of heaviness is felt. When the food is overloaded, the stone causes more pain, especially when the food descends into the intestines; when the body is freed and the excess flows out of the intestines, the pain becomes quieter. As for the signs of stone movement, the pain moves downwards and intensifies. They descend from the lower back to the groins and ureters, and here the stone brings the torment to the limit. And when the pain calms down, it means that the stone has settled in the bladder.