When TB affects the kidneys, symptoms are often different than when it affects the lungs. When symptoms appear, they often resemble those of a urinary tract infection. Timely treatment is important to prevent complications.

Renal tuberculosis (TB) is a relatively uncommon form of TB that affects your kidneys. The same bacteria that can cause TB in your lungs also causes renal TB.

TB is a highly infectious disease, most common in Africa and South Asia. According to the World Health Organization (WHO), around 10.6 million people globally caught TB just in 2021. But renal TB is relatively rare.

Somewhere from 5–45% of new TB cases are extrapulmonary, meaning that they affect organs other than your lungs. Renal TB belongs to a type of TB that affects your urinary and reproductive systems known as urogenital TB. It accounts for 30–40% of all extrapulmonary TB cases.

Renal TB is the most common form of urogenital TB.

This article will discuss renal TB, including its causes, symptoms, and treatment.

Mycobacterium tuberculosis is the bacterium typically responsible for renal TB. However, other species of this bacterium (for example, Mycobacterium bovis) can also cause this condition.

The infection usually occurs due to bacteria traveling through the bloodstream from the infected tissues in the lungs to the kidneys. TB bacteria are usually inactive in kidneys but can reactivate in people with weakened immune systems, such as those with HIV.

Less common causes of renal TB include transmission through the lymphatic system and sexual transmission.

Other types of urogenital TB

Other types of urogenital TB include:

Not all people with renal TB have symptoms. Those who do may have the following:

These symptoms don’t necessarily mean you have renal TB. More likely, they can indicate other conditions of your urinary system.

But because these symptoms are similar to other conditions, like urinary tract infections, many people with renal TB receive an incorrect or late diagnosis. This can result in delayed treatment.

Be sure to speak with a doctor if you have any urinary symptoms, especially if you have a weakened immune system or other risk factors for TB.

Is TB of the kidney contagious?

Renal TB is not contagious by itself. But if you have active pulmonary TB along with TB in the kidneys, you can transmit the infection to others when coughing or sneezing.

It’s crucial to take precautions and seek medical attention if you suspect you have TB.

To diagnose renal TB, a doctor will first perform a physical exam. They’ll ask you about your medical history, including if you have a history of TB or HIV.

They’ll also likely order different tests, including:

A primary care doctor will likely refer you to a nephrologist (kidney doctor) and an infectious disease specialist to check your progress. Treatment of renal TB is typically the same as for pulmonary TB.

Usual TB treatment consists of a combination of antibiotics used over 6–9 months. Doctors usually use a combination of the following drugs:

  • isoniazid
  • rifampin
  • pyrazinamide
  • ethambutol

Antibiotics used to treat TB can sometimes cause complications, including liver damage. Tell your doctor about new or alarming symptoms during your treatment, for example:

Left untreated, renal TB can cause structural damage to your kidney, which can result in kidney failure. Some people with complicated renal TB may need surgery to remove the affected kidney (nephrectomy).

But TB antibiotics are typically very effective in preventing complications. Be sure to complete the course as prescribed by the doctor and attend all follow-up appointments.

With early diagnosis and treatment, the outlook for people with renal TB is usually very good. Antibiotic treatment is typically effective and can eliminate the bacteria, resolve inflammation, and prevent complications.

Be sure to discuss your outlook with a doctor, as it can vary based on your situation.

Renal TB is a form of tuberculosis that affects your kidneys. Left untreated, it can cause serious complications, including kidney failure. But treatment is usually very effective.

Be sure to seek medical attention if you have any urinary symptoms. If a doctor diagnoses you with renal TB, it’s essential you complete the treatment course to get rid of the bacteria completely.