Kidney Pain

Kidney pain is typically a sharp painful sensation that is felt on the lower part of back of human body, on either side of the backbone. It is also called renal pain.

There are two bean shaped kidneys that are present in human body on the lower part of back, on either side of backbone. These kidneys perform various functions in human body, of which, filtration of blood, urine formation and fluid and electrolytes balance are the most important functions.

The renal pain is in waves or cycles most of the time. If the renal pain is felt that means there is something wrong with the kidney which is causing the painful sensation in the renal area (lower back of human body).

COMMON CAUSES OF RENAL PAIN:

Sharp renal pain which is typical renal pain is felt most of the time due to these reasons:

• Kidney infections also called pyelonephritis i.e. inflammation of kidney tissue. Due to inflammation the kidney increases in its size, causing its capsule (surrounding the kidney) to stretch. The capsule of kidney is pain sensitive and thus pain is felt due to its stretching.

• Kidney stones are one of the most common reasons of the renal pain.  Due to abnormal kidney function or abnormal increase in certain substances in body, different substances depending upon the cause are deposited inside kidney forming the hard, stone like masses. These hard stone like masses are called kidney stones. In the worst case scenario, these stones can break from kidney or a part of them is broken and travel all the way to the ureter (narrow tubes extending from kidneys to bladder). In the ureter these stones cause irritation or even blockage so that the flow of urine is stopped. The kidney pain caused by renal stones is called colic (meaning pain that occurs in waves).

• Urinary tract infections are also one of the common causes of the kidney pain. This condition is more common in women as they are more affected by urinary tract infections as compared to the men. Most commonly gram negative bacteria cause these infections. They can cause infection of urethra, bladder and up to the kidneys. If the kidneys are involved, there is inflammation of kidneys causing kidney pain and other signs and symptoms of this condition include fever, vomiting and nausea as well.

Dull renal pain which is not generally typical renal pain is felt most of the time due to following reasons:

• Polycystic kidney disease in which several cysts (sac like structure typically filled with fluid) are formed inside kidney. These cysts causes enlargement of kidney thus stretching the capsule and causing pain. It is a genetic disease. In this case, the characteristic features of kidney pain are different. The pain is dull and aching and instead of back region of abdomen, it is felt in the front region of the lower abdomen.

• Kidney cancer, normally, does not cause any kidney pain. It grows silently without any signs and symptoms. However, in some cases, the growth of tumor is so large, that it increases the kidney size and thus stretches the capsule of kidney and pain is felt. But that pain is mostly dull in character.

• Blocked urine flow is due to different causes for example; one cause of blockage is chronic bilateral obstructive uropathy.

DIFFERENCE BETWEEN BACK PAIN (DORSALGIA) AND KIDNEY PAIN:

As both are felt at the back of the abdomen, they should be distinguished from each other:

• The back pain is predominant on all the back of the body including thorax and abdomen while the kidney pain is felt on lower part of back of abdomen, above the hips and to the left or right side of the spine (backbone).

• Back pain is dull, sudden and may be continuous/intermittent while the kidney pain is severe, sharp and occurs in waves mostly and is accompanied by fever, chills and pain on urination.