Kidney contusion

Introduction / definition

A kidney contusion is a Injury to one or both kidneys, by blunt violence was caused without directly destroying tissue in the organ. The kidney bruise becomes the Kidney trauma counted, in their graduation from degrees 1-5 they the Grade 1 corresponds. The kidney contusion, also called Renal contusion is defined as a bruise (Hematoma), which inside the connective tissue capsulethat surrounds the kidney is and is does not expand further over time. The functional kidney tissue is thereby just repressedbut is not damaged. This is different with a higher-order kidney trauma. About two-thirds the recorded Kidney injuries become the Assigned to grade 1. The kidney trauma Grade 2, in which one himself spreading hematoma arises, and Grade 3 like the kidney contusion Treated conservatively.

With kidney trauma Grade 4 and 5 can severe injuries the kidneys and the urinary tract exist. Here it can be Destruction of part of the functional tissue the kidneys come that The lower urinary tract can also be affected or completely torn off. This must be surgically be treated.

The kidney contusion, however, is a mostly well healing occurrence, should to rule out a worse finding, however medically clarified become. Most kidney contusions will come through Sports or traffic accidents come about, besides are also Bodily harm a possible reason.

Why should a kidney contusion be seen by the doctor?

The kidneys, of which humans usually have two, are among the main organs of the body. They lie on both sides of the spine, roughly below the navel line. Besides the Production of urine and thus maintaining the water balance in the body, the kidney still has other important tasks. she filters dangerous toxins with the urinethat the body cannot break down from the blood and eliminates them. Also the Maintaining the correct proportions of salts (electrolytes) dissolved in the blood is done by it. Besides regulated the kidney in large measure the blood pressure and takes care of the correct adjustment of the pH valuewhich must be kept within narrow limits.

Also Hormones are produced by the kidneys. Because of this diversity, an injury to one or both kidneys can occur depending on the severity consequences that should not be underestimated entail. A kidney contusion leads, however not to destroy kidney tissue and the function is thus retained. However, a kidney contusion should be treated and if it is suspected it is A visit to the doctor is essentialsince one at this point do not estimate the extent of the injury can. Not only the kidney could have been affected, but also neighboring organs or bone.


Due to the blunt forceMostly responsible for kidney contusion are the symptoms diverse and partially relatively unspecific. After an injury or an accident, the symptoms must do not occur immediately but can also appear with a slight delay. In all cases a severe pain in the flank described. The pain quality is often a dull, boring or stabbing pain specified. This is laterally at the back at about the level of the navel localized. It is possible that the pain continues into the Emits belly and back.

It is not uncommon for patients to come to the clinic who severe back pain and tension specify. This does not mean that if you have back pain you should immediately suspect a kidney contusion, only if it had previously occurred Event such as a fall or a violent blow In the back or in the side, back pain can be the result of a kidney contusion. This pain can also be from Causes cramps because of a kidney contusion due to the close networking of the nerve plexuses Back muscles can cramp. At the The surface of the body are hematomas, so seeing bruises with one Swelling of the tissues can go hand in hand.

The main seminal symptom in the diagnosis of kidney contusion is that Hematuriawhat translates Blood in the urine means and can appear in two forms: Macro and micro hematuria. In the Macrohematuria whole intact red blood cells are detectable in the urine and the person concerned can a red discoloration to the naked eye see. The Microhematuria, on the other hand, tends not to stain the urine, because they are components of destroyed red blood cells that have lost their characteristic color in their present form. It is important to know that a Normal-colored urine does not rule out bleeding from the kidneys. However, this symptom comes with one Variety of diseases and is therefore not specifically attributable to the kidney contusion. Also urinary tract infections or urinary stones hematuria can occur. Likewise exists no connection between the extent of the hematuria and the severity of the injury. Still that is Observation of the hematuria an important criterion for the course of treatment for the attending physician.

Another symptom is associated with a kidney contusion nausea reported that only in the further course of Vomiting accompanied becomes. If you have moderate symptoms, you can go to bed at home. However, it is important to pay attention to the course of the symptoms. If these get worse or remain the same for a long time, a doctor must be consulted.


Most kidney bruises are caused by sports or traffic accidents.

50% of kidney injuries are caused by blunt force, that is, large and wide-area forces act on one part of the body. In this case the Force from behind laterally hit on the back, as the kidneys are right here. Also a Hit the flank can cause kidney contusion. However, this force must be considerable, because a kidney contusion is one rather rare injury.
Typical situations in which this constellation is given are Accidents and Contact sports situations. Bodily harm are also on the list of possible reasons, if not at the top. A Fall from a certain height also carries the risk of this injury. As part of a blunt abdominal trauma With strong force from the front, kidney contusions can occur, but in these cases it is the kidney usually about the degree of a kidney contusion damaged and requires a completely different approach.


The diagnosis of a kidney contusion is with appropriate means pretty easy deliver. The Main focus lies on it worse damage to the kidneywhich in the worst case have to be surgically repaired, to exclude. The doctor begins initially with the anamnese of the patient. Be here systematic acute discomfort, pain and previous events queried.

A Slap in the back or on the side This can lead in the right direction before the symptoms appear. There follows one clinical examination. Here the doctor pays attention to visible signs of kidney contusion like Redness, swelling of the flank and bruising and the affected area is scanned. A occurring tenderness is almost always present in kidney contusions.

In addition, a Urine sample be taken and this on the Checks for the presence of blood become. To get blood under a Microhematuria are to be proven special test strips that discolor even if the urine looks normal. These simple and quick methods can then be carried out various imaging procedures added if the doctor cannot safely conclude that there is a kidney contusion or if they want to rule out other accompanying injuries that are not apparent at first glance.

Of the Ultrasonic represents a possibility of imaging. Herewith can not exactly these Assessment of the severity of the trauma, but a distinction can be made between a kidney contusion and a more serious injury to the kidney. In the picture, only the kidney bruise is shown under the capsule See hematoma. So there is an apparent one Kidney enlargement in front.

The complex out detailed questioning, history and clinical signs in connection with the ultrasound image and the Urinalysis are sufficient to diagnose a simple kidney contusion. However, if the doctor is unsure whether the injury extends beyond a kidney contusion, they should further measures be seized. For one accurate assessment of the kidneys can a Computed tomography be useful. It shows the whole body in detail in sectional images and allows statements to be made about the extent, areas involved and neighboring damage caused by the injury.
The disadvantage of CT is that Hno radiation exposure. However, this allows sure more serious injuries exclude.

The MRI (magnetic resonance imaging) plays a rather subordinate role and is due to the high costs used at most during a follow-up. When diagnosing Children can the MRI could be interesting because of the lack of radiation exposure. If the kidney is slightly bruised, neither CT nor MRI are used.

Figure bruise

Figure bruise: types and examples

Bruise - Contusio
A - joint contusion (1-6)
B - Bruised bone (7, 9, 14)
C - Bruises of internal organs (12)
D - muscle contusion (10, 13)
E - Nerve contusion (8, 11)

  1. Shoulder joint -
    Articulatio humeri
  2. Elbow joint -
    Articulatio cubiti
  3. Upper wrist -
    Articulatio radiocarpalis
  4. Hip joint -
    Articulatio coxae
  5. Knee joint -
    Articulatio genus
  6. Upper ankle joint -
    Articulatio talocruralis
  7. head
  8. Neck, shoulder, neck area
  9. Ribs
  10. Upper arm - Brachium
  11. Forearm -
    Antebrachium (Ulnar nerve)
  12. Internal organs
    (Kidney, liver, spleen, intestine, etc.)
  13. Thigh - Femur
  14. Shin - Tibia
    Examples of a bruise:
    Picture a - Knee joint contusion
    Picture b - calf muscle contusion

You can find an overview of all Dr-Gumpert images at: medical illustrations


After the injury you should rest and possibly with light pressure from the outside cool. Each physical activity should be avoided and the doctor should be consulted. This can be traced back to what is well known in muscle and joint injuries PECH rule notice. PECH stands for Break, ice, compression and elevation. Due to the location of the kidneys, elevation doesn't make much sense here, but the other measures are also suitable for kidney contusions. Still is important much liquid to take in to aid healing. The guidelines for treating kidney trauma are that a kidney contusion should always be diagnosed conservative therapy sufficient.

Operative interventions are only at higher level trauma of the kidneys. Conservative in this case means Bed rest for days or 1-2 weeks and a adequate pain medication with known active ingredients such as Diclofenac or Ibuprofen. From the outside supplied heat when showering or bathing the Aggravate pain and should be avoided. In addition, warmth promotes blood circulation, which is counterproductive in the event of a bruise. Usually, kidney contusions can be controlled this well until the symptoms subside and the injury heals.

In the course is one Ultrasound check-up and a Urinalysis to recommend. It is possible that a hospitalized done for a few days. Most of the time, however, a visit to the family doctor or a referral doctor who can prescribe painkillers after the kidney contusion is diagnosed is sufficient. After about a week, an appointment will be made again Monitor the healing process.


A kidney contusion usually occurs without any complications. In rare cases, however, kidney contusions can lead to complications. Especially elderly or debilitated people can be affected. One possible complication is one Inflammation of the renal pelvis or the lower urinary tract. The tissue irritated by the shock is temporarily weakened and so more prone to inflammation.
In some cases, the leaking blood can also promote inflammation, especially in debilitated patients. Occurs in addition to the existing symptoms of kidney contusion fever on, this requires one more detailed clarification. Usually a short one fixes Administration of antibiotics the problem. Secondary bleeding can also occur, which is why you should especially in this case close monitoring of the urine status should control.


The kidney contusion is one painful injury. However that is Risk of long-term damage is very low. Usually heals the kidney contusion of alone in a few days. Accordingly, the forecast the kidney contusion Well. It is only dangerous if a more serious injury is trivialized and mistaken for a kidney contusion and consequently remains untreated.