Urinary Tract Infection, in short UTI, is an infection that occurs anywhere in your urinary system, the kidneys, ureters, bladder, or urethra [1].
If a urinary tract infection of the lower tract (i.e. bladder) is not treated, the infection can either spread to the kidneys and cause pyelonephritis [2], or the infection can also spread to the prostate and testis in men, causing prostatitis and orchitis respectively.
Recurrent cystitis (bladder infection) is a risk factor for developing squamous cell carcinoma of the bladder due to chronic inflammation [3].
Hence, it is important that you do not leave your UTI untreated. Do consult a doctor as soon as possible.
References:
1. hhs.gov. Urinary Tract Infection (UTI). HHS.gov. Published May 19, 2019. Accessed December 13, 2019.
2. Mariya Belyayeva, Jeong JM. Acute Pyelonephritis. Nih.gov. Published February 28, 2019. Accessed December 13, 2019.
3. Bladder cancer - Symptoms and causes. Mayo Clinic. Published 2017. Accessed December 13, 2019.