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Foods that Trigger Kidney Stones


Kidney stones are collections of salt and mineral in the urine. Though they aren’t a serious condition, kidney stones can cause severe pain. If you’re prone to kidney stones, avoid the following foods:

Excessive caffeine

Too much caffeine can cause a range of health problems, including kidney stones. Excessive intake of coffee, tea and soda can stress out the kidneys, leading to higher calcium levels in the urine.

Foods that are high in Oxalate

Foods high in Oxalates cause a person to pass excess Oxalate though their urine. This can result in the formation of calcium-oxalate stones. Some foods that are high in Oxalate include sweet potatoes, spinach, beans, white corn and soy products.


High-calcium foods

Calcium is an important part to any diet. However, increasing calcium intake too much can cause calcium formations to end up in the kidneys. Limit milk, cheese and other dairy products if you get kidney stones.

Refined white sugar

Refined white sugar causes the body to produce high levels of insulin, which causes calcium from the bones to end up in the urinary tract.

Foods high in proteins

Diets that are high in protein can lead to an increase in uric acid and kidney stone formation. Lean protein is an important part of your diet. However, decrease the consumption of sardines and red meat to limit your chances of getting kidney stones.

Kidney Stone Treatment

If you’re suffering from kidney stones, or would like to learn more about the prevention or treatment of kidney stones, please contact Pentucket Medical at (888) 227-3762.

Evaluating Treatment Options for Kidney Cancer


The most common type of kidney cancer is called renal cell carcinoma. Several treatment options are available, including surgery or medical treatment.

The choice of treatment depends upon the stage of the cancer. The “stage” describes the size and aggressiveness of the cancer, including whether it has spread to other parts of the body (such as the lungs, liver, or bones). Lower stage cancers are generally not as advanced and are less likely to come back after treatment.

Treatment Options for Localized Renal Cell Carcinoma

Localized kidney cancer includes stages I through III. It is called localized because the cancer has not yet spread beyond the kidney (except for nearby lymph nodes, which are part of the body’s immune system).

Kidney Surgery

Surgery to remove part or all of the affected kidney is the preferred treatment for most people with localized kidney cancer. How much tissue is removed depends upon:

  • size and location of the cancer in the kidney
  • number of tumors present
  • how well the kidneys work.

If the tumor is large or in the center of the kidney, your doctor may remove the entire kidney, as well as nearby areas that are affected (radical nephrectomy). This is more likely to be done if the other kidney works well. Fortunately, most people are able to live well with just one kidney.

If the other kidney is not functioning properly, the surgeon may remove only part of the kidney in order to allow the kidney to keep working, at least somewhat. This can be done either surgically, or by freezing or burning the kidney tumors.

Advanced Renal Cell Carcinoma

Advanced (or metastatic) renal cell carcinoma consists of stage IV kidney cancer. This type of advanced cancer is difficult to cure.

Medical Treatments

Medicine (also known as medical treatment) is used instead of, or in addition to, kidney surgery.

Three of the main types of medical treatment are:

  • Interleukin-2 (IL-2). This therapy turns on the immune system so that it attacks the cancer cells. It is usually only used when you are healthy enough to withstand the severe side effects, such as fever, kidney failure, low blood pressure, and irregular heart beat.
  • Anti-angiogenic therapies. This medical treatment keeps new blood vessels from forming and supplying the tumor with the blood that it needs to grow and survive. This will not cure the kidney cancer, but can stop the tumor from growing for a long time. Side effects include tiredness, high blood pressure, and rashes.
  • Targeted therapies. These medicines slow the growth of the cancer by interfering with the cancer cells directly. This treatment also won’t cure the kidney cancer, but can help you live longer with fewer symptoms. Side effects include tiredness, high blood pressure, and rashes.


Surgery for advanced renal cell carcinoma is sometimes used before medical treatment, although medical treatment may be done on its own.

Surgery can be done robotically where the surgeon uses a high tech machine, called the da Vinci robot. The arms of the robot are controlled by the physician and it mimics the doctor’s hand movements precisely. This allows the surgeon to reach areas within the body without having to make large incisions and without seriously damaging skin and tissue.

As with localized kidney cancer, all or part of the kidney is removed. Treatment for advanced kidney cancer, though, also involves removing areas outside of the kidney where the cancer has spread (metastases).

Surgery does not usually cure the cancer in cases of advanced renal cell carcinoma, but may reduce the symptoms and allow you to delay medical treatment.

Radiation or Chemotherapy

Radiation or chemotherapy may be used after surgery in both localized and advanced kidney cancer. These are used to kill left-over cancer cells, even if all of the visible cancer was removed. This lowers the risk that the kidney cancer will return.

With radiation therapy, X-rays or another type of radiation is used to kill the cancer cells. The radiation source is either outside the body (as with the X-rays) or placed inside the body (using a radioactive substance).

Chemotherapy drugs—taken by mouth or injected—kill the cancer cells or stop them from growing.

Follow-Up Tests

Regular check-ups after treatment are advised in order to make sure that the cancer does not return. This may include an exam, lab tests, and X-ray tests, and are done every 6 to 12 months for at least five years.

Nephrologists: The Hypertension Experts

Hypertension, or high blood pressure, is a difficult problem to treat. Usually hypertension develops later in life and requires treatment with dietary changes, exercise, weight control, and sometimes medications. Uncontrolled hypertension can have serious consequences, including stroke, heart attacks, peripheral vascular disease, blindness, and even kidney failure. However, there are times when high blood pressure can be associated with other diseases that need to be diagnosed and treated.

Treating high blood pressure is challenging, and may in some cases have a secondary cause. Nephrologists are hypertension experts, trained in the evaluation and treatment of high blood pressure.

Secondary causes of hypertension

  • underlying kidney disease
  • obesity
  • sleep apnea
  • uncontrolled diabetes
  • hormonal disorders (thyroid glands, adrenal glands)
  • kidney artery disease

If your primary care doctor is treating you with 3 or more medications for blood pressure, and your blood pressure still is running high, then you may need to see a nephrologist to help identify the cause of your hypertension, and to help treat it in order to get it under better control.

Pentucket Medical offers Nephrology services in the following locations.

All About Proteinuria

What is proteinuria?


Proteinuria is the presence of protein in the urine. It can often be a sign on kidney disease. Normally, protein should not be found in the urine.

What causes protein to leak in the urine?

Healthy kidneys do not allow a significant amount of protein to pass through their filters. But filters damaged by kidney disease may let proteins such as albumin leak from the blood into the urine.

What are the different kinds of proteinuria?

Transient proteinuria — Most common form of proteinuria. Can be seen with stresses such as fever and exercise. Transient proteinuria is usually resolved on its own and does not require treatment.

Orthostatic proteinuria — Loss of protein in the urine, occurs while in an upright position but not when lying down. Occurs in 2-5% of adolescents, and is unusual in people over age of 30 years. It typically disappears with age, is not harmful and does not require treatment.

Persistent proteinuria —Protein that is always present is often a sign of underlying kidney disease or other medical problems such as hypertension and diabetes mellitus.

Who should be tested?

Patients should be tested for proteinuria if they have any of the following risk factors:

  • Diabetes
  • Hypertension
  • Chronic kidney disease
  • Family history of chronic kidney disease
  • Cardiovascular disease
  • Kidney stones or structural kidney disease

How would you doctor diagnose proteinuria?

Urine testing/ urinalysis — It can be detected by a quick dipstick test in the office; however dipstick testing is not very precise. It is very important to repeat the test, as it may be transient and repeat test can be normal. Microscopic examination of the urine is done to see if there are cells, crystals, bacteria, or structures called casts. These urine elements and suggest specific types of kidney problems.

What if protein in the urine is noted on more than two occasions?

Your doctor will send it to the lab to quantitate it.

  • A single urine sample collected at any time.
  • Urine that has been collected over 24 hours

Blood testing — Your doctor or nurse may also ask you to have blood tests to check your kidney function.

Kidney biopsy — Your doctor might recommend a test called a kidney biopsy, during which a doctor takes a small piece of one kidney and then looks at the tissue under the microscope. Most people with protein in the urine do not need kidney biopsy.

What are the signs and symptoms of protein in the urine?


Proteinuria may have no signs or symptoms in the early stages. Large amounts of protein in the urine may cause it to look foamy in the toilet. Swelling in the hands, feet, abdomen, or face may occur.


How is proteinuria treated?

Proteinuria is not a specific disease. Treatment depends on identifying and managing its underlying cause. If that cause is kidney disease, appropriate medical management is essential.

Untreated chronic kidney disease (CKD) can lead to kidney failure.

In mild or temporary proteinuria, no treatment may be necessary.

Drugs are sometimes prescribed, especially in people with diabetes and/or high blood pressure. These may come from two classes of drugs:

• ACE inhibitors (angiotensin-converting enzyme inhibitors)

• ARBs (angiotensin receptor blockers)

Where can you find more information?

8 Risk Factors for CKD

Chronic kidney disease (CKD) is a silent disease, generally without any symptoms, so it is often difficult to know if you indeed have it. Risk factors for CKD include :

  • Hypertension
  • Diabetes
  • Family history of kidney disease
  • Smoking
  • Obesity
  • Frequent urinary infections or history of frequent kidney infections (pyelonephritis)
  • History of certain types of chemotherapy
  • History of frequent kidney stones

If you have any of these risk factors, talk to your doctor about getting screened. Your doctor should test you for CKD with blood and urine tests.

To learn more about Chronic Kidney Disease and treatments, see last week’s blog from Dr. Josh Tarkan.

To make an appointment with Pentucket Medical Nephrology in Haverhill or Newburyport, call 888-227-3762.

The Scoop on Salt

Salt facts

Salt (sodium chloride) is a necessary component for the functioning of all cells in the body, and the body cannot manufacture sodium. Without sodium we could not transport nutrients or oxygen, transmit nerve impulses, or move muscles, including smooth and skeletal muscle. Salt regulates the water content of the body. An adult human being contains about 250 grams of salt, which would fill three to four saltshakers, but salt is lost continually through sweat, urine, and stool, and must be replaced. Salt deficiency causes headaches, weakness, and nausea, and ultimately death. Acute salt overdose (1 gram per kg body weight) can lead to death. Chronic salt overload is thought to contribute to hypertension and congestive heart failure.

Salt intake

Controversy abounds regarding our optimal salt intake. The prevailing message is that we should avoid salt intake. The CDC has suggested that reducing salt consumption is as important to long-term health as quitting smoking. Yet, the reduced salt initiative is somewhat difficult to defend. Some evidence over the past few years suggests that restricting salt intake may actually increase our likelihood of dying prematurely, but this evidence is not very strong.

Most Americans consume 3400 milligrams of sodium per day, which is well above the current guidelines, which suggest that healthy people consume no more than 2300 milligrams per day. Keep in mind that sodium comprises 40% of salt itself (sodium chloride), so that 3400 milligrams of sodium equals 8.5 grams of salt. There are data to suggest high salt intake corresponds to higher blood pressure and by extension, increased cardiovascular and stroke risk, and worsening kidney function, though most of these studies have some flaws. The lower limit of sodium intake is also not well-defined, as there are data that show that those on very low sodium diets have worsened cardiovascular outcomes. Most experts agree that 2300 milligrams sodium intake per day is a reasonable target for those above age 51, those with hypertension, kidney disease, or African-Americans.

Other benefits of low salt diets

Other benefits of low salt diets include decreased risk of osteoporosis, decreased risk of kidney stones, improvement in heart muscle stiffness, and improved response to insulin.

High sodium foods

Processed foods are typically high in salt. This includes deli meat, canned soups, and condiments. Ten types of foods account for more than 40 percent of sodium consumption in the US. Breads/rolls, deli meat, pizza, soups, cheeseburgers, cheese, pasta, potato chips, pretzels and popcorn are known culprits. It has been estimated that 89% of Americans’ salt intake is salt already embedded in the food before it is prepared. The best way to lower sodium intake is to avoid foods in cans, jars, boxes and bags. Try for meals containing 600 mg sodium or less.

Low salt diets

Most experts agree that it takes only three weeks to retrain your taste buds to accept a lower salt diet. Consider flavoring foods with lemon, rosemary, garlic, and pepper. Also try to avoid salt substitutes; many contain potassium which may be harmful to those on certain medications.

Salt labels

FDA Food Labeling Guide

l Requires disclosure if sodium content exceeds 480 mg sodium per serving

l Light sodium = usual level reduced by 50%

l Reduced sodium = usual level reduced by 25%

l Low sodium = 140 mg or less per serving

l Very low sodium = 35 mg or less per serving

l Sodium-free = very tiny amount of sodium per serving

Chronic Kidney Disease: An Overview

Chronic kidney disease (CKD), also known as chronic renal disease, affects 17 percent of adults aged 20 or older in the United States. CKD is defined as a progressive loss of kidney function taking place over months to years. In the U.S., diabetes and hypertension are the leading causes of kidney disease, but other conditions may also contribute to a decline in kidney function, such as autoimmune disease (sometimes leading to what we call glomerulonephritis, or inflamed kidney filters), vascular problems, polycystic kidney disease, kidney stones, and blockage of urine.


Screening for CKD usually includes a urinalysis (UA), and a blood test called a creatinine level. The normal creatinine value varies with age and amount of muscle mass.


The kidneys perform many functions, most importantly the filtering of blood and clearing toxins, and by removal of excess salt, water, and electrolytes from the body. The kidneys are also involved with creating red blood cells, and with bone health. Symptoms of CKD include fatigue, intolerance to cold temperature, and nausea. In later stages, some might experience anemia (low blood count), fluid overload, high blood pressure, and problems with electrolytes including calcium, phosphorus, and potassium.


The stages of Chronic Kidney Disease are determined by a patient’s GFR, or glomerular filtration rate. The GFR is the amount of blood cleaned by the kidneys per minute. Normal GFR value for a male is 130 mL per min and normal for a female is 120 mL per min.

There are five “stages” of CKD:

  • Stage I = GFR >90 mL/min with some evidence of structural problems involving the kidneys, perhaps blood or protein in the urine
  • Stage II = GFR 60-89 mL/min
  • Stage III = GFR 30-59 mL/min
  • Stage IV = GFR 15-29 mL/min
  • Stage V = GFR 0-14 mL/min

Some describe a sixth stage of kidney disease, or end-stage renal disease (ESRD).


Patients with ESRD require a transplant or dialysis to survive. Most patients with CKD, however, do not succumb to kidney failure, but rather cardiovascular disease, which is quite prevalent in patients with kidney disease. The best ways to slow the progression of CKD are by obtaining goal blood pressure levels (usually with medications that block the renin-angiotensin-aldosterone pathway such as ACE inhibitors or ARBs), by controlling blood sugars in those with diabetes, and by avoiding NSAIDS (nonsteroidal anti-inflammatory drugs).


Typically a nephrologist (kidney specialist) will get involved once the kidneys are functioning below a GFR of 60 mL/min. Nephrologists can help slow the progression of CKD and can treat some of the sequelae of kidney disease (e.g. anemia, bone disease), and can prepare patients if dialysis is approaching.

What to Expect at your Nephrology Appointment

At your office appointment, you may see the Nephrologist (kidney specialist) or the nurse practitioner (advanced practice nurse). They work closely together to manage your care and often alternate visits with you.

At the appointment you will:

  • have your weight checked
  • have your blood pressure checked
  • review your medications
  • have a physical exam (check your lungs, heart, legs for swelling)
  • leave a urine sample (to check for infection, protein, blood)
  • likely have blood drawn to check your kidney function and other kidney related lab tests
  • review any recent test results or discuss any further tests needed
  • discuss a plan of care- next appointment, any medication changes, lab tests needed, diet recommendations

What you can do to prepare for your appointment:

  • bring an updated list of medications
  • bring a list of any questions/concerns you have
  • if you have had lab work don at an outside location, make us aware at the visit
  • if you check your blood pressure at home, bring your blood pressure cuff to the visit so we can check your cuff
  • if you check your weight at home, bring a few recent weights