From popping painkillers to shortage of sleep: 7 common habits that could be harming your kidneys

Over 10% of people in the UK have chronic kidney disease. Avoid these 7 everyday habits that could silently harm your kidneys and impact overall health.

In the UK, more than 10% of the population is estimated to have some stage of chronic kidney disease and more than 600,000 people develop some form of acute kidney injury – when the kidneys suddenly stop working properly but can recover – each year.

The kidneys play a vital role in maintaining overall health by filtering waste, excess fluids and electrolytes, such as sodium and potassium, from the blood. They also help regulate blood pressure, red blood cell production and calcium balance in the body. When the kidneys are damaged, their ability to filter waste and maintain balance is compromised, leading to a buildup of toxins, fluid retention and an imbalance in electrolytes.

This can cause a range of health problems, from high blood pressure to heart disease and weakened bones. Kidney damage can progress to chronic kidney disease and kidney failure over time. Kidney damage, then, can affect almost part of your body – but there are simple lifestyle changes you can make today to avoid harming your kidneys tomorrow.

Here are seven potentially kidney-harming habits to avoid:

1. Using painkillers

Common over-the-counter anti-inflammatory painkillers like ibuprofen and aspirin can damage the kidney tubules – tiny tubes in the kidneys that return filtered nutrients and fluids back to the blood. The remaining fluid and waste in the renal tubules become urine – and inflammation and reduced blood flow through the kidneys. This is more likely to occur in older people or those with other medical conditions.

People who already have chronic kidney disease should avoid these painkillers unless they’ve been prescribed by a doctor who can monitor kidney function. To lower the risk of side-effects, use painkillers for the shortest time needed at the recommended dose on the packaging.

2. Not drinking enough water

Water is needed for the kidneys to remove waste. People who don’t drink enough water may be risking kidney damage, especially in hot weather. Concentrated urine from dehydration has higher levels of minerals and other waste products – this increases the risk of kidney stones and urine infections, which may damage the kidneys.

Some people with health conditions such as liver disease or heart failure may be on restricted fluids. But for the general population, between 1.5 to 2 litres of water (about six to eight cups) daily is recommended.

3. Drinking too much alcohol

The kidneys regulate the water in the body. Alcohol can dehydrate the body, which therefore changes how the kidneys work. Too much alcohol can also raise blood pressure, which damages the kidneys. Most people know that alcohol can contribute to liver disease, but this in turn can harm the kidneys as it means they have to work harder.

The NHS advises men and women to not drink more than 14 alcohol units per week (ideally spread throughout the week with some alcohol-free days). This equates to one standard glass of wine (two units) or a pint of low-strength beer (two units) per day.

4. Smoking

Most people know that smoking can contribute to cancers and heart disease. But smoking can directly harm the kidneys through multiple mechanisms. Cigarette smoke contains toxic chemicals such as cadmium which may harm the kidneys. Smoking promotes oxidative stress (when harmful molecules called free radicals damage cells in the body) and can narrow the blood vessels and damage the blood vessel lining which can lead to kidney injury.

Smoking also increases the risk of other conditions that can damage the kidneys, including diabetes and high blood pressure. There is no safe level of smoking, so it’s best to quit with support from a healthcare professional.

5. Being overweight

A healthy body mass index (BMI) is between 18.5 and 24.9. Anything over this is classed as overweight or obese. However, this isn’t the only measure of being overweight – and is sometimes inaccurate. The waist circumference is a good measure of fat around the middle (central obesity) which is shown to increase the risk of heart disease and diabetes – two common causes of kidney disease. Obesity might harm kidneys directly by disrupting fat tissue chemicals.

Having a healthier diet in conjunction with exercise can help shed the pounds, helping keep your kidneys healthy. Some research has found that physical activity lowers the risk of kidney disease – aim for 30 minutes of aerobic exercise five days a week but build it up slowly.

6. Making less healthy food choices

Ultra-processed foods (UPFs) are manufactured foods that contain ingredients such as fats, sugars, salts, and additives including artificial colours, flavourings and preservatives to make them taste better and increase their shelf life.

Examples of UPFs include meats such as sausages, carbonated soft drinks and packaged breads. These foods are linked to various health issues, such as obesity, heart disease and type 2 diabetes. Recently it has also been linked to kidney disease. An American study tracked 14,000 adults for 24 years. Those who ate a lot of ultra-processed foods had a 24% higher risk of kidney disease. Nearly 5,000 of them developed chronic kidney disease.

Diets high in salt (sodium) can also be problematic, especially in people who already have kidney disease. The kidneys filter excess water from the blood, needing a balance of sodium and potassium. A high salt diet disrupts this balance, reducing kidney function and causing higher blood pressure, which strains the kidneys and can lead to kidney disease. Stick to a maximum of six grams – or one teaspoon – of salt per day.

7. Poor sleep

There is some evidence that links sleep quality and duration with kidney disease. A study has shown that poor sleep increases the risk of chronic kidney disease. Research differs slightly but having less than six hours or more than ten hours of sleep daily may harm your kidneys. Optimal sleep tends to be between seven to nine hours per night for most people. Factors such as age and family history are beyond your control but many habits can be changed to help manage kidney health.