AfterOurs Clinics - Colorado
AfterOurs Clinics - Colorado

Mild Kidney Infections

Woman sitting on the sofa
A kidney infection usually occurs when bacteria, most frequently Escherichia coli (E. coli), get into the urethra and then travel through the bladder to the kidneys. Mild kidney infections are not serious, and in most cases, antibiotic therapy is sufficient. In the case of serious infection, a person will be admitted into the hospital to receive intravenous (IV) antibiotics and any other support that person may need.


The major cause of kidney infections is usually Escherichia Coli, a bacterium that lives in the intestines and is normally expelled with feces. Other bacteria can also cause kidney infections, such as Staphylococci, Enterobacter and Klebsiella.

Some risk factors for kidney infection include:
  • Use of an indwelling or straight urinary catheter
  • Immunocompromise
  • Frequent sexual intercourse
  • Anatomic abnormalities that “trap” bacteria

Kidney infections usually ascend from the genital area, through the urethra, to the bladder, to the ureters, and finally the kidneys. In a person with a healthy urinary tract, the risk of infection from the ureters to the kidney is prevented by the flow of urine that carries away the microorganisms and by the closure of the ureters at the point of entry into the bladder. However, any type of physical blockage (obstruction) of urinary flow, such as a structural abnormality, kidney stone, or enlarged prostate, may increase the likelihood of kidney infections.

Kidney infections can occur at any age, but they are much more prevalent in women who than men. This happens because the female urethra is shorter than the male urethra, making it easier for bacteria to reach the kidneys. In many cases of kidney infection, only one of the two kidneys is affected.


Common symptoms associated with mild kidney infections are:
  • Pyrexia (burning with urination)
  • Nausea and vomiting
  • Pain in the mid back
  • Frequent urination
  • Urgency with urination
  • Fever and body aches
  • The appearance of pus or blood in the urine
  • Cloudy or pungent smelling urine


Mild kidney infections are commonly treated with antibiotics. For specific treatment, a medical provider will run tests, including urine culture, to identify the exact type of infection.

In case of a serious kidney infection, a patient will be admitted to the hospital so that proper treatment can be administered.