A kidney infection, medically known as pyelonephritis, is a serious form of urinary tract infection (UTI) affecting one or both kidneys. It typically occurs when bacteria, often from the bladder, ascend the urinary tract to the kidneys. Recognizing its signs is important for prompt treatment and to prevent complications.
Recognizing the Signs
A kidney infection often presents with a range of symptoms that can appear suddenly, sometimes within a few hours or days. Pain is a common indicator, typically felt in the lower back, side (flank area, just below the ribs), or groin. This pain can be aching or sharp, reflecting the inflammation within the kidney itself.
Urinary symptoms also frequently accompany a kidney infection. These include a burning sensation or pain during urination, a persistent and urgent need to urinate, and increased frequency. Urine might appear cloudy, dark, or contain blood, and it can have a foul odor. These changes reflect the body’s response to inflammation and bacteria in the urinary tract.
Beyond localized pain and urinary changes, systemic symptoms indicate the body’s broader response to the infection. These include a high temperature, chills, and shivering. Nausea and vomiting are also common, along with fatigue and muscle aches. In very young children, a kidney infection might only manifest as a high fever, while older adults may experience confusion or mental changes.
Confirming a Diagnosis
Confirming a kidney infection typically involves medical evaluation and laboratory tests. A healthcare professional will review your symptoms and medical history, including any previous urinary tract infections.
Physical examination is also part of the diagnostic process, which may include checking for tenderness in the back or flank area. The primary diagnostic tools are urine tests. A urinalysis checks for signs of infection such as white blood cells, red blood cells, or bacteria in the urine. A urine culture is then performed to identify the specific type of bacteria causing the infection, guiding the choice of appropriate antibiotic treatment.
Blood tests may also be conducted to assess for broader signs of infection, such as an elevated white blood cell count, or to check kidney function. In cases where complications are suspected, or if infections are recurrent, imaging tests like an ultrasound or CT scan of the kidneys might be used. These imaging studies can help identify any structural issues in the urinary tract that might contribute to the infections.
When to Seek Immediate Medical Care
A kidney infection requires prompt medical attention and should not be left untreated. If symptoms suggest a kidney infection, seek care from a healthcare provider to avoid serious complications.
Certain symptom combinations or individual circumstances necessitate immediate medical consultation, potentially at an urgent care center or emergency room. These include a high fever, severe pain in the back or side, persistent nausea, or vomiting that prevents keeping fluids down. Rapidly worsening symptoms or signs of dehydration, such as reduced urination, also warrant immediate evaluation.
Individuals with underlying health conditions, such as diabetes, a weakened immune system, or those who are pregnant, should seek urgent care if they suspect a kidney infection. These conditions can increase the risk of more severe outcomes. Delaying treatment can allow a lower urinary tract infection to progress to a kidney infection.
Potential Health Consequences
Untreated or inadequately treated kidney infections can lead to several serious health complications. One significant risk is permanent kidney damage, manifesting as scarring of the kidney tissue. This damage can impair kidney function over time, potentially contributing to chronic kidney disease and high blood pressure.
In some cases, severe kidney infections can progress to kidney failure, where the kidneys lose their ability to filter waste from the blood effectively. Another serious complication is the spread of bacteria from the kidneys into the bloodstream, leading to a life-threatening condition known as sepsis. Sepsis is an inflammatory response that can result in organ dysfunction and can be fatal.
For pregnant individuals, a kidney infection can increase the risk of complications such as premature birth or low birth weight. Recurrent kidney infections can also occur, particularly if there are underlying structural problems in the urinary tract that are not addressed.
Overview of Treatment Approaches
Antibiotics form the primary treatment for kidney infections, as these medications target the bacteria causing the infection. The specific type of antibiotic and the duration of treatment depend on the severity of the infection and the bacteria identified through urine culture. While symptoms often begin to improve within a few days of starting antibiotics, it is important to complete the entire prescribed course to ensure the infection is fully cleared.
In more severe cases, hospitalization may be necessary to administer antibiotics intravenously. This method allows the medication to enter the bloodstream directly, often resulting in a faster response, especially for individuals who are very unwell or cannot tolerate oral medications. Hospital stays typically range from a few days to a week, during which time medical staff monitor the patient’s condition and the effectiveness of the treatment.
Supportive measures are also part of the treatment plan. Pain management can involve over-the-counter pain relievers to alleviate discomfort and reduce fever. Staying well-hydrated by drinking plenty of fluids helps to flush bacteria from the urinary tract, but alcohol and caffeine should be avoided as they can irritate the bladder. If an underlying issue, such as a urinary tract blockage, contributes to recurrent infections, further investigations and potentially surgical correction may be considered.