As the UK experiences a heatwave, joint preservation specialist Professor Paul Lee is highlighting the often-overlooked impact of dehydration on the body's joints and cartilage. While many people associate heatwave hazards with sunburn, heat exhaustion, or general dehydration, Professor Lee warns that cartilage relies heavily on water to function correctly.
Cartilage Needs Hydration Like a Sponge
Professor Lee explained that cartilage is approximately 70% to 80% water. Unlike many other tissues, cartilage lacks a direct blood supply and obtains nutrients through fluid movement within the joint. When dehydration sets in, this process becomes considerably less efficient.
He said: "Most people think about dehydration in terms of feeling thirsty, tired or dizzy. What they often don't realise is that cartilage is approximately 70% to 80% water. It relies on hydration and movement to maintain joint health."
Professor Lee added: "Cartilage behaves a little like a sponge. It needs hydration and movement to help nutrients circulate through the joint. If the body is dehydrated, the environment the cartilage depends on becomes less favourable."
The 'Rule of Six' for Hydration
To help people maintain proper hydration during hot weather, Professor Lee recommends adhering to what he calls the "rule of six". The guidance includes:
- Do not go more than six hours without drinking water during the day
- Do not go more than six hours without passing urine while awake
- If your urine is darker than a pale straw colour, increase your fluid intake
- Drink more if you are sweating heavily
- Avoid excessive alcohol consumption during hot weather
- Seek medical advice if you become dizzy, confused or stop passing urine normally
Professor Lee said: "I often tell patients to protect their cartilage with the 6x6 rule. Stay hydrated enough to pass pale urine at least every six hours. It's a simple way to monitor whether your body is getting enough fluid."
Who Should Be Most Cautious?
This guidance is especially crucial for older individuals, those living with arthritis, and anyone spending extended periods outside during the heatwave. While staying hydrated alone won't prevent joint issues entirely, Professor Lee maintains it remains one of the most straightforward measures people can take to support their body's natural processes.
He added: "We often focus on exercise, treatments and medications, but basic hydration is one of the foundations of healthy joints. During a heatwave, people should not wait until they feel thirsty."
"By then, dehydration may already be affecting how the body functions. Looking after your joints can be as simple as making sure you're drinking enough water and paying attention to the signals your body is giving you."
