By Dr Milton Lam

THE diagnosis of urinary tract infections (UTI) is made from the history presented by the patient, a physical examination, and laboratory investigations. The clinical features of UTI may differ depending on whether the lower, i.e. bladder or urethra, or upper urinary tract, i.e. kidney, is involved.

The clinical features suggestive of UTI involving the bladder (cystitis) include pain or a burning sensation when passing urine, frequent passing of urine, feeling the urge to pass urine, lower abdominal discomfort or pain, urine that smells or appears cloudy or red, and tenderness in the lower abdomen.

The clinical features suggestive of UTI involving the kidneys (pyelonephritis) include frequent passing of urine, pain when passing urine, feeling the urge to pass urine, aches in the back, groin and side of the body, fever, blood and/or pus in the urine, nausea, vomiting, and tenderness in the back.

Clinical features of the factors that increase the risk of UTI may also be present. These factors have been discussed in the article a fortnight ago.

Sometimes, symptoms are less specific and they include tiredness and confusion. The latter is more common in senior citizens. It is advisable for anyone with these symptoms to seek medical attention.

Many people who are suffering from UTI have no symptoms at all. This is particularly so in the case of people who are at increased risk of UTI, e.g. pregnancy, diabetis.

Other conditions which may have symptoms similar to that of a UTI include common infections of the genital tract, e.g. sexually transmitted infections and fungal infections of the vulva and vagina, urethral syndrome (a condition in which the symptoms indicate a UTI but there is no underlying infection), non-infective cystitis due to nonsteroidal anti-inflammatory and other drugs, and an enlarged or infected prostate in men.

The distinction between an uncomplicated and a complicated UTI is important as it has an impact on the type and choice of antibiotics, and the extent to which the urinary tract will be evaluated.

Certain factors suggestive of a potential complicated UTI include male gender, senior citizens, pregnancy, diabetes, abnormalities of the urinary tract, recent antibiotic use, immunosuppression, symptoms present for a week or more, indwelling urinary catheter, and hospital acquired infection.