Pain in the kidney, characterized by pain in the lower back is a very common complaint in the general population. However, contrary to what most people believe, the vast majority of cases of back pain is not caused by the kidneys, but the spine and adjacent structures.
Low back pain by back problems and kidney pain are completely different and have different causes.
Most people have two kidneys, which are located parallel to the spine, usually between the 12th thoracic vertebra of the spine (T12) and the 3rd lumbar vertebra (L3). The left kidney is usually located slightly higher than the right. The kidneys are retroperitoneal organs, or are located closest to the back, behind the abdominal cavity, protected by the rear portion of the ribs.
The ureters and kidneys (tubular channels that carry urine from the kidneys to the bladder) are highly innervated, allowing to feel pain when they suffer any harm or inflammation. This rich renal innervation, however, intersects with the nerve fibers coming from other structures and nearby organs, including the skin nerves coming. As a result, the brain finds it difficult to specify the origin of the pain. So it is not uncommon for the pain of a kidney or ureter injury pain may arise in distant places, such as stomach, testicles or ovaries.
In general, the pain of the kidneys is poorly defined and diffuse laterally affecting the lower back and the flanks.
Renal pain may be precipitated by renal ischemia (reduced blood supply), inflammation / infection of the kidneys, traction or distention of the renal pelvis or distension of the capsule covering the kidneys.
In practice, this means that the following injury and kidney disease usually the most common causes of kidney pain:
Renal calculus
Infection of the kidneys (pyelonephritis)
Polycystic kidney disease
Hydronephrosis (obstruction passage of urine, resulting in dilation of the kidney)
Contrary to popular belief, renal failure, whether chronic or acute, do not cause kidney pain. Even in advanced stages, the pain in the kidney is not part of the symptoms of patients with renal failure. This information is important since most patients with renal impairment is elderly, age in which back problems are very common. It is very common renal insufficient patients have back problems, but unfairly blame the kidneys for their pain.
Chronic kidney failure is a silent disease until very advanced stages. Even patients already on hemodialysis not feel kidney pain, unless you also have any of the problems listed above.
Pain in the kidney has its own characteristics depending on the disease responsible for their appearance. Besides the pain itself, the associated symptoms are very helpful in clarifying the question.
Examples:
The pain of kidney stones, called renal colic, is a unilateral excruciating back pain, perhaps the worst pain the patient already has meaning in life. It comes suddenly gets worse over the next few hours and does not improve with nothing, leaving the patient extremely restless. No use up, lie down, sit, bow, massage the back ... nothing works! The patient is "crazy" with pain. It is common to vomiting and blood in the urine. The pain of kidney stones may radiate to the flanks or groin area.
The pain of kidney infection called pyelonephritis, is a unilateral back pain that usually comes associated with fever, chills, poor general condition, nausea and vomiting. Low back pain has nothing to do with position of the trunk or column movements. Sit, lie down or stand not interfere with pain. However, light punches in the lower back can aggravate the pain, which is a maneuver that doctors use during physical examination.
Low back pain of patients with polycystic kidney disease is more difficult to distinguish. In addition it may have characteristics similar to those of back pain such as aggravation by walking or after movements of the trunk, is kidney is large, it can itself cause overloading of the muscles and ligaments of the lumbar spine, leading to chronic low back pain.
Patients with polycystic kidney pain may be due to various causes, including increasing the size of the cysts, bleeding or rupture of a cyst, kidney infection, kidney stones, etc. In addition, polycystic kidney can also cause abdominal pain if it is too large.
Differences between pain in the kidney and back pain
The main differential diagnosis for pain in the kidney is the pain of muscle origin skeletal lumbar spine, known as lumbago. In fact, most cases of low back pain originates from the spine and its ligaments and muscles. Only a small fraction of cases is actually renal origin.
The main feature of pain musculoskeletal diseases of the spine is the fact that this has mechanical characteristics, i.e. it is a pain that worsens with movement and in certain positions, but usually ease with rest. The source musculoskeletal pain can also cause certain rigidity, preventing the patient to make movements with the column. Other common features are the radiation of pain to the leg, and can go up to knee height, muscle weakness in the legs and loss of sensation in the lower limbs.
The back pain usually more drawn frames with moderate intensity of pain that last for months or even years. In most cases there are other symptoms such as fever, vomiting, blood in the urine, loss of appetite, etc.
To summarize, in general, it is easy to distinguish renal origin musculoskeletal pain of low back pain. Not only the characteristics of pain are often very different, as well as the associated symptoms are completely different.
