UTIs in humans are not considered contagious in the same way colds or the flu are. You generally cannot “catch” a UTI just from being around someone who has one.
What contagious means here
A typical UTI happens when bacteria from a person’s own gut (often E. coli) enter the urethra and travel into the bladder or other parts of the urinary tract. This means the infection usually comes from the person’s own bacteria, not from direct transmission like coughing, sharing drinks, or casual contact.
Sex and partner-to-partner risk
Sex does not usually transmit a UTI itself, but sexual activity can move bacteria between partners and into the urethra, which may trigger a new UTI in someone who is susceptible. Because of this, UTIs are not classed as sexually transmitted infections, even though sex can increase the risk of getting one.
Situations that are very low risk
UTIs are not caught from toilet seats, normal hugging, kissing, sharing towels, or using the same bathroom. The bacteria involved usually need to get directly into the urethral area and then up into the urinary tract to cause an infection, which normal casual contact does not do.
When to see a doctor
Anyone with burning when urinating, needing to pee very often, lower abdominal pain, or fever should be evaluated, because a UTI can sometimes spread to the kidneys if untreated. Medical care is especially important if there is back pain, fever, or feeling very unwell, as these can be signs of a more serious infection.