Aging changes in the kidneys and bladder

How the urinary system changes

The kidneys clean the blood by removing waste and excess fluid, while helping maintain the body’s chemical balance. Urine travels through the ureters to the bladder and leaves through the urethra. These organs work together, so a problem with storage or emptying can have consequences beyond the bladder.

With age, kidney tissue and the number of filtering units, called nephrons, decrease. The blood vessels supplying the kidneys may harden, slowing filtration. In an otherwise healthy person this loss of function is generally slow; illness, medicines and other conditions can cause a more substantial decline.

The bladder wall becomes less elastic and its muscles may weaken. It can therefore hold less urine and may not empty as effectively. Changes in muscles and reproductive organs also influence bladder control.

Leakage, retention and obstruction

Urinary incontinence means that urine escapes unintentionally. Retention means that the bladder does not empty completely. They are different problems and both become more likely with age, alongside urinary tract infections and chronic kidney disease.

The urethra may be partly or completely obstructed. In women, weakened supporting muscles can allow the bladder or vagina to drop from its usual position, called prolapse. In men, an enlarged prostate can narrow the route through which urine leaves. These problems should be assessed individually.

Preparing for a useful assessment

Notice what has changed from your usual pattern. A clear description helps your clinician distinguish urgency, leakage and trouble emptying, and consider whether illness or medication is contributing.

• Note when symptoms began, how often you urinate and whether there is burning, pain or leakage.
• Bring a list of your medicines and mention recent illnesses or changes in treatment.
• Discuss persistent bladder-control problems; do not assume they have no possible treatment.

When to get medical help

Contact a healthcare professional promptly if urinary symptoms are new or worsening. Seek immediate assessment if you cannot pass urine, especially with pain or a swollen lower abdomen.

• Fever or chills, burning on urination, nausea, vomiting, marked tiredness or pain in the flank may indicate an infection.
• Fresh blood or very dark urine needs assessment.
• Difficulty urinating, noticeably more frequent urination or a sudden urgent need to urinate should be discussed promptly.