Smoking And Your Kidneys: What You Should Know

Does smoking affect your kidneys? The short answer is “yes.” Smoking can speed up the progression of chronic kidney disease, contribute to the risk of kidney cancer, and cause renal artery stenosis.

Kidneys are highly resilient organs that play a significant role in your body’s flawless operation. However, many outside factors can affect the health of your kidneys, including smoking.

Smoking can have various adverse effects by slowing down the blood flow to your kidneys and elevating your blood pressure. It can cause problems for people who already have chronic conditions and those who are otherwise healthy. Let’s take a closer look at how it works.

Smoking and chronic kidney disease

Chronic kidney disease (CKD) affects around 15% of American adults¹, but 90% don’t know they have it. In the early stages, CKD doesn’t have any symptoms. 

The signs of advanced CKD include:

• Fatigue

• Nausea and vomiting

• Poor appetite

• Dry skin

• Headaches

• Sleep problems

• Unexplained weight loss

• Muscle cramps

CKD can progress without proper treatment and lifestyle changes and lead to kidney failure. If you are a smoker, this habit can worsen the symptoms.

According to studies², smoking contributes to the progression of chronic kidney disease. Clinical studies demonstrated that cigarette smoking worsens CKD in people with diabetes, hypertension (high blood pressure), and polycystic kidney disease. It can also exacerbate the symptoms of CKD in people who have had a kidney transplant.

Another study³ looked at 198 patients with stage 3 or higher CKD. It found that smoking increased the risk of CKD significantly. The risk of CKD was the highest among smokers who had diabetic nephropathy and hypertensive nephropathy.

The same study demonstrated that heavy smoking (more than 30 packs per year) is a significant risk factor for chronic kidney disease.

According to data from the Multiple Risk Factor Intervention Trial⁴, smoking increases the risk of reaching end-stage kidney failure.

How does smoking affect your kidneys?

Smoking can hurt your kidneys in many ways. The main problem is the disruption of proper blood flow to the arteries.

Higher blood pressure  

Smoking causes a temporary increase in blood pressure. Smokers who already have blood pressure problems suffer from these spikes the most. If you continue to smoke but don’t address the blood pressure issue, your kidneys will suffer.

Kidneys are surrounded by a significant number of blood vessels. If blood pressure is high all the time, these vessels become weaker and narrower. When this happens, they can’t deliver blood to the kidneys properly.

Damaged kidney arteries reduce the kidney’s ability to filter blood. In turn, damaged kidneys can’t help the body regulate blood pressure, making the process a vicious cycle. As artery damage gets worse, your kidneys start failing.

Albuminuria 

Albuminuria is a condition when you have too much albumin in your urine. Albumin is a special protein that helps move molecules through your blood and keeps the fluid in your blood from leaking into the tissues.

When your kidneys are healthy, they don’t allow albumin to enter your urine. A damaged kidney may allow some albumin to pass. If a urine test reveals high levels of albumin in your blood, it may be a sign of kidney disease.

Smokers have higher albumin levels in urine than non-smokers do. One study⁵ demonstrated that smokers have significantly higher urinary albumin levels than non-smokers. Levels of albumin are directly proportional to the quantity of smoking.

Renal artery stenosis 

Renal artery stenosis is a condition when one or more arteries that carry blood to your kidneys begin to narrow. The narrowing of these arteries keeps oxygenated blood from reaching your kidneys. When this happens, the kidneys lose the ability to filter waste products properly.

While more research needs to be done, one study⁶ already demonstrated that smoking could cause renal artery stenosis at a younger age. It also indicated that smoking could lead to higher mortality rates in patients with renovascular hypertension (high blood pressure caused by kidney artery problems).

Kidney cancer

Renal cell carcinoma⁷ (RCC) is the most common kind of kidney cancer. This cancer starts as a tumor in one or both kidneys. If detected early, it’s possible to cure this condition by surgery. In recent years, the number of RCC cases has been rising steadily.

Smoking increases your chances of developing RCC. The risk is related to the quantity of smoking. It starts dropping as soon as you quit smoking. However, it may take several years for it to go down to the levels of a non-smoker.

Benefits of quitting smoking for people with CKD

Quitting smoking is an important decision for people with chronic diseases, and CKD is no exception. While many people develop CKD throughout their lives, hardly all end up with complications. Making timely lifestyle changes is key to preventing unfortunate consequences.

Prevent excessive progression of the disease 

While quitting smoking won’t treat CKD, it can slow its progression. Since kidney disease often worsens over time, doctors use specific criteria to diagnose the problem.

A special test called eGFR (estimated glomerular filtration rate) checks how well the kidneys are working. Based on the test results, the doctors determine the stage of your CKD:

• Stage 1—eGFR is 90 or higher – slight damage that doesn’t prevent the kidneys from working normally

• Stage 2—eGFR is between 60 and 89 – mild damage that can still allow kidneys to function normally

• Stage 3 (a and b)—eGFR is between 30 and 59 – mild to severe damage that keeps kidneys from working as they should

• Stage 4—eGFR is between 15 and 29 – severely damaged kidneys are close to failing

• Stage 5—eGFR less than 15 – kidneys are either very close to failing or stop working

People with stage 5 kidney disease require regular dialysis or a kidney transplant. If your CKD is still in its early stages, you may be able to keep it from progressing by making lifestyle changes and quitting smoking.

A study⁸ showed that quitting smoking can prevent eGFR levels from decreasing. It demonstrated that continued smoking contributed to continuing GFR decline. While albuminuria increased over time in smokers, non-smokers, and quitters, it did so the most in smokers. For non-smokers and quitters, the levels were similar.

Higher quality of life 

When you start experiencing the first symptoms of CKD, your quality of life can decrease. People with chronic kidney disease always feel tired, struggle with sleep issues, and face continuous stress related to their health.

By quitting smoking, you aren’t just slowing down the progression of your kidney problems. You are contributing to your overall well-being.

People at both earlier and later stages of CKD suffer from a decreased quality of life. Increasing it is highly important for your life expectancy. Quitting smoking improves your quality of life significantly. 

Soon after quitting, you can enjoy:

• Better hearing and vision

• Clearer skin

• Stronger muscles and bones

• Healthier sex life

• Better lung function

Studies⁹ show that the life expectancy for smokers who quit at 35 exceeds that of smokers by 6.1 to 8.5 years. The younger you are when you quit, the more you can extend your life. People who quit at 65 managed to extend their life by 1.4 to 3.7 years.

Lower risks of developing other health problems 

Living with CKD is hard enough. Developing other chronic problems doesn’t just decrease your quality of life, it can worsen existing conditions too. By quitting smoking, you can lower the risk of developing other health problems, including:

• Cancer

• Cardiovascular problems

• High cholesterol levels

• Chronic obstructive pulmonary disease

Women who quit smoking before pregnancy can reduce the risk of pre-term delivery and fetal growth issues.

The lowdown 

Smoking can have a significant effect on your kidneys. It can contribute to the progression of chronic kidney disease, increase the risk of developing kidney cancer, and affect your quality of life.

By quitting smoking immediately, you can reduce the risks tremendously, improve your general health, and prevent existing kidney disease from progressing rapidly.

Since quitting smoking isn’t easy, you may need help. CDC has numerous helpful resources¹⁰ that can get you started.

Frequently asked questions 

Can smoking affect my kidneys?

Smoking can hurt your kidneys by damaging arteries that supply blood to the organs. It can also increase the risk of kidney cancer and speed up the progression of chronic kidney disease.

Is foamy urine a sign of kidney disease? 

A foamy urine could be a sign of kidney damage. If it happens regularly, schedule an appointment with your primary care physician.

Is smoking a problem for people with high blood pressure?

Smoking increases blood pressure temporarily. For people with blood pressure problems, such spikes could worsen the condition and lead to other health issues, such as kidney problems.