Does Alcohol Affect Your Kidneys?

Drinking alcohol to excess is linked to several health problems, including liver disease and an increased risk of certain cancers. But can alcohol damage kidneys, too?

The short answer is: Yes.

Nephrologist Priyanka Jagannath, MD, explains the direct and indirect relationship between alcohol and kidney diseases.

How alcohol harms kidneys

Regular, heavy alcohol use can be harmful to your kidneys, both in the short term and over time. That makes sense because your kidneys are responsible for:

• Filtering waste from your blood
• Regulating the balance of water and minerals in your body
• Producing hormones

And all that work is harder to do when your kidneys are busy processing alcohol.

According to the National Kidney Foundation, regular heavy drinking can double your risk of developing chronic kidney disease (CKD). The risk is even higher if you smoke, too.

Heavy drinking also has an indirect effect on kidney health.

“Think of your body as a big domino set,” illustrates Dr. Jagannath. “If one area of your health is out of balance, it can lead to problems elsewhere.”

Let’s review some of them.

Dehydration

Alcohol makes you urinate more than usual. If you aren’t replacing those lost fluids, drinking can leave you dehydrated. That’s bad news for your kidneys, which need fluid and electrolytes to function properly.

“Severe dehydration decreases the volume of blood in your veins,” Dr. Jagannath explains. “That means your kidneys have to work harder than usual to filter waste and keep your electrolytes in balance.”

Over time, chronic dehydration raises your risk for certain types of kidney damage. But the relationship isn’t always clear.

For example, research hasn’t yet shown that heavy drinking is a direct cause of kidney stones. But we know that dehydration is.

“If you drink a lot of alcohol and don’t drink enough water, it would make sense that you have a greater chance of developing kidney stones,” she continues. “Even if there isn’t a connection, staying hydrated is always a good idea — especially if you’re drinking alcohol.”

Increased workload

When you drink heavily, your kidneys have to work harder to filter out the alcohol. And in rare cases, binge drinking — consuming four or five drinks in two hours, depending on your sex — can cause a sudden drop in kidney function. That’s called acute kidney injury.

Acute kidney injury occurs when toxins from alcohol build up in your blood so fast that your kidneys can’t maintain the proper fluid balance. Though it’s reversible with treatment, it can increase the risk of developing chronic kidney disease later.

High blood pressure and Type 2 diabetes

Excess drinking can increase your risk of developing chronic health conditions, like high blood pressure (hypertension) and Type 2 diabetes, which happen to be the two most common causes of chronic kidney disease (CKD) in the United States.

“High blood pressure and Type 2 diabetes strain your kidneys by damaging the tiny blood vessels that filter waste and excess fluids,” Dr. Jagannath explains. “Over time, that added strain can impact your kidneys’ ability to function properly.”

Inflammation and oxidative stress

Oxidative stress caused by alcohol consumption, whether during a single binge-drinking episode or over the long term, can cause inflammation and contribute to kidney scarring (renal fibrosis). That tissue damage can reduce kidney function and may even lead to a CKD diagnosis down the line.

Liver damage

You probably already know that chronic alcohol use is a major cause of liver disease. But did you know that liver damage can affect your kidney function, too? When your liver isn’t functioning well, it can impair blood flow to your kidneys.

“Liver disease can have significant impacts on your kidney function,” says Dr. Jagannath. “The two organs work together. So, when your liver is compromised, it increases the strain on your kidneys, too.”

Signs of kidney damage from alcohol

If you drink heavily, keep an eye out for the following signs of kidney damage:

• Changes to the amount, frequency, color or consistency of your pee
• Unexplained weight gain
• Pain in your lower back or between your ribs and hip (your flank)
• Fatigue that doesn’t improve with rest
• Swelling in your legs, feet, ankles or face

Not sure what counts as “heavy drinking”? You may be surprised. In the U.S., heavy drinking is defined as:

• For women: More than eight drinks per week or more than four drinks in a single day.
• For men: More than 15 drinks per week or more than five drinks in a single day.

“If you’re having trouble with alcohol, seek medical help,” Dr. Jagannath urges. “It’s nothing to be ashamed of, and your healthcare providers have a lot of avenues to help you find the support you need.”

Alcohol and kidney pain

We’ve reviewed the many ways drinking affects your kidneys, but you may have noticed something’s missing. What about the kidney pain some people claim to feel after a night of drinking? Is that unpleasant pang a sign of kidney damage?

According to Dr. Jagannath, there’s no research to suggest a link between alcohol and kidney pain. But dehydration can cause muscle spasms. If a glass of water and a relaxing shower aren’t doing the trick, call a healthcare provider. You could be dealing with another issue, like kidney stones or an infection.

Can kidneys recover from alcohol damage?

Whether your kidneys can recover from damage caused by excessive alcohol depends on a lot of different circumstances. Your best bet is to speak with a healthcare provider about it. They can’t make any promises, but they can paint a picture of your recovery odds based on:

• The type and severity of the damage your kidneys sustained
• Your past and current medical history
• Your drinking habits (how much you drink, how long you’ve been drinking, etc.)
• Whether you’re still drinking

Even if the damage is irreversible, making lifestyle changes can prevent further damage down the road.

“Diet, exercise, sleep, hydration and reducing substance use can help protect your remaining kidney function and improve your overall health,” Dr. Jagannath encourages.

Protecting your kidney health if you drink alcohol

If you aren’t looking to give up alcohol, but want to keep your kidneys as healthy as possible, Dr. Jagannath recommends that you:

• Limit your consumption. The less alcohol you drink, the better off your kidneys are. But how much is too much depends on a lot of different factors. When in doubt, ask a healthcare provider.
• Stay hydrated. Drink water (or better yet, an unsweetened sports drink) before, during and after consuming alcohol.
• Track key health indicators. Check your weight, blood pressure and (if you have diabetes) your A1C every couple of weeks using home monitors. If you notice changes, alert a provider. They can order kidney function tests if needed.

By staying informed, being proactive and making mindful choices about your alcohol consumption, you can support your kidney health for years to come.