Kidney problems

• tiredness
• nausea and vomiting
• swollen ankles or feet
• frequent urination (especially at night).

There aren’t usually signs in the early stages of kidney damage; they tend to show later when the condition is more advanced.

The old version of the antiretroviral drug tenofovir (also found in the combination drugs Truvada, Atripla and Eviplera) was linked to kidney problems, but the new drug which has replaced it appears to be safer for kidneys.

This new version of the drug, called tenofovir alafenamide (TAF), is less toxic for the kidneys than the older version tenofovir disoproxil fumarate (TDF), and people switching to it show improved kidney function.

Some drugs from the protease inhibitor class –  atazanvir, lopinavir (found in Kaletra) and the rarely-used indinavir –  have been linked to kidney stones. These are crystals which form inside the kidney, over time forming a ‘stone’. The stones can cause pain when the body tries to pass them out through the bladder.

Most people with HIV will be offered regular kidney function tests.

Tests often look for protein in the urine, as it should only be found in the blood. They also look for creatinine, a waste product, in the blood. If the levels of creatinine are high, the kidneys are having trouble removing it. High blood pressure and diabetes can be picked up in routine tests and may be a sign of kidney damage.

If kidney problems become more serious, they might require dialysis, which filters waste products from the blood. It’s also possible to have a kidney transplant if necessary. Having HIV doesn’t exclude you from this.

Chronic kidney disease (CKD) is when other conditions such as high blood pressure and diabetes put strain on the kidneys.

This leads to a gradual loss of kidney function, which can result in kidney failure. Diabetic people may have high glucose levels in their blood which can damage the kidneys' nephrons (part of the kidneys’ filtration system). High blood pressure can put strain on the blood vessels which surround the nephrons, causing damage.

HIV can cause specific kidney damage known as HIV-associated nephropathy (HIVAN) where the kidneys become enlarged.

HIVAN tends to be more common in African people or people of African descent. Usually HIVAN improves on antiretroviral treatment, which is why it’s much less common now.

Similarly CKD seems to be more prevalent among Black and south Asian people. This is probably because there are higher rates of diabetes in south Asian people and higher rates of high blood pressure among Black people.

Most people have two kidneys, located on each side of the spine towards the back of the tummy (although many people function with just one).

Kidneys filter toxins and waste products from the blood. These are then converted into urine and expelled from the body via the bladder. Kidneys also release hormones to regulate blood pressure and the production of red blood cells, as well as helping the body to absorb calcium.

If you think you might have developed a problem with your kidneys, talk to your doctor at your HIV clinic. They might be able to help you or adjust your treatment if necessary.