Celibates are less likely to succumb to urinary tract infections than are people who are sexually active . In pregnancy , the developing foetus causes mechanical obstruction of the urinary flow. This leads to an increased risk of urinary tract infections. The introduction of a urinary catheter greatly increases the risk of the patient developing an infection. Neurological problems that affect bladder emptying, including spina bifida and multiple sclerosis, are associated with an increased risk of urinary tract infections.
Dysuria is also a common feature of urethritis caused by some sexually transmissible pathogens.
Infected urine may be cloudy. This can be due to the presence of pus in the urine - known as pyuria . If infected urine appears dark in colour , this may be due to the presence of blood - haematuria . Urinary tract infections can ascend above the bladder to cause pyelonephritis . Symptoms of urinary tract infection can mimic those of acute appendicitis .