Most people meet a nephrologist, a kidney specialist, only after a lab result raises a flag. By then they already have a primary care doctor, a cardiologist and perhaps an endocrinologist, each looking at one part of the picture.

Dr. Yana Shtern is board certified by the American Board of Internal Medicine in both internal medicine and Nephrology. That combination matters more than it might sound in a primary care practice, because the kidneys sit at the center of several conditions that are common after 50.

Kidney disease is common and usually silent

The CDC estimates that more than 1 in 10 U.S. adults have chronic kidney disease, about 37 million people. It is more common with age: about 34% of adults 65 and older, compared with 13% of those 45 to 64. The same report estimates that about 9 in 10 adults with CKD do not know they have it.

That last number is the reason screening matters. According to the NIDDK, most people in the early stages of CKD have no symptoms, and for many the only way to know is with blood and urine tests.

Blood pressure and the kidneys go together

The NIDDK names diabetes and high blood pressure as the most common causes of CKD in adults. High blood pressure can damage the blood vessels and filters in the kidneys. Damaged kidneys then have a harder time removing extra fluid, which can raise blood pressure further.

The CDC estimates that more than 2 in 10 adults with high blood pressure have CKD. So when blood pressure is hard to control, a doctor trained in Nephrology will look at the kidneys as a possible cause as well as a possible victim. Our high blood pressure page describes how we approach it.

Diabetes, kidneys and the heart

About 4 in 10 adults with diabetes are estimated to have CKD, according to the CDC. The NIDDK explains that high blood glucose can damage the kidneys’ filters over time, allowing protein to leak into the urine.

Two tests do most of the work in checking the kidneys. A blood test estimates how well the kidneys filter, reported as eGFR, and a urine test looks for albumin, a protein that a healthy kidney keeps out of the urine. The NIDDK describes both on its page about kidney tests. An internist who is also a nephrologist reads those results in the context of your blood sugar, blood pressure and medicines, all at once.

Medicines and kidney function

This is where the overlap is most practical. Many medicines leave the body through the kidneys. The NIDDK notes that when kidneys do not filter as well, medicines can build up to unsafe levels, some medicines can harm the kidneys, and a doctor may change how much or how often you take a medicine as kidney function changes.

Over-the-counter pain relievers are a common example. The NIDDK warns that NSAIDs such as ibuprofen and naproxen can damage the kidneys, especially in people with kidney disease, diabetes or high blood pressure. We cover this in more detail in NSAIDs: risks and side effects.

Some blood pressure medicines, on the other hand, can help. The NIDDK notes that two classes, ACE inhibitors and ARBs, may slow kidney disease. Choosing among options, and checking labs after a change, is easier when one doctor is watching the whole list.

What this looks like in practice

Having both trainings in one doctor does not replace a separate Nephrology practice for everyone. People with advanced kidney disease, dialysis or a transplant usually need a dedicated kidney team. For many patients with early or stable CKD, though, it can mean fewer handoffs and one clear plan.

  • One reading of the labs: kidney numbers, blood sugar and cholesterol reviewed together.
  • One medicine list: checked against your current kidney function before anything is added.
  • One conversation: blood pressure, diabetes and kidney health discussed as linked problems.
  • Coordination when needed: if you already see a kidney specialist, notes can be shared both ways.

It also helps with the questions people ask most often: what a borderline eGFR means for them, whether a new medicine prescribed elsewhere suits their kidneys, or whether a change in a lab result is worth repeating the test. Those are judgment calls, and they are easier with training in both fields.

Labs are drawn in our office, so kidney tests can be done during a regular visit. Our kidney care page describes the practice’s approach in more detail.

If you have been told your kidney numbers are borderline, or you are managing blood pressure and diabetes together, a complimentary meet and greet with Dr. Shtern is a good place to start. Bring your recent lab results and your medicine list, and we can talk through what they show.

This article is general information, not advice for your situation. Members can call the office with questions about their own care.