My Weekly’s favourite GP Dr Sarah Jarvis from TV and radio writes for you
You take it for granted that if you’ve had a lot of fluid to drink, you’ll need to pass more urine. But do you know where your urine is made? If not, you’re in good company. One survey suggested that half of the participants didn’t know the kidneys were responsible for making urine.
Most people have two kidneys, each about the size of a fist, that sit on either side of your spine, just below your ribcage. They each weigh less than 170g (6 ounces) – but they process 180 litres (40 gallons) of blood every day through a million tiny filters. In fact, they use a quarter of the blood pumped out every time your heart beats.
Your kidneys filter out waste products and toxins from your bloodstream, but they also carry out a host of other functions you couldn’t live without.
Every cell in your body depends on having a very precise amount of minerals and water to keep it functioning efficiently.
Your kidneys adapt what they let through and reabsorb into your system to keep this balance just right.
If you’re dehydrated, they’ll reabsorb more water, so your urine will be more concentrated. Messages from hormones made by your body tell them how to adapt the balance.
Your kidneys also help regulate your blood pressure. High blood pressure is one of the biggest risk factors for heart attack and stroke.
If your kidneys aren’t working properly, your blood pressure will go up. But high blood pressure can also damage your kidneys.
That’s one of the reasons it’s so important to get your blood pressure checked regularly. High blood pressure doesn’t cause symptoms in the short-term, so you won’t know you’ve got it unless you have it tested.
If you’re diagnosed with high blood pressure, it’s important to keep it under control to protect your kidneys as well as your heart.
Too much sodium from salt in your diet can increase your risk of high blood pressure. As a nation, we eat over 8g of salt a day – way above the recommended maximum of 6g.
Cooking from scratch and using herbs and spices (rather than salt) to flavour food can help to cut down your intake.
A reduced sodium alternative such as
