Real Madrid attacker Cristiano Ronaldo says he has not been pain-free for quite some time as the knee injury that troubled him toward the end of the 2013-14 campaign continues to cause problems.

The 30-year-old has not missed a single minute of action so far this campaign for Madrid, while he hardly missed a game in 2014-15 as well.

However, that does not mean the knee problems that nearly kept him out of the 2013-14 Champions League final and away from the World Cup no longer cause him issues.

"There is not a single day without pain. Every player will say the same. It's part of the job and you have to deal with it," the Madrid star told Kicker.

"I now realise things [what] I didn't realise when I was younger. I have always tried to improve and you gain more experience over the years. 

"When I was 22, 23 years old, I often went out for dinner after a game and got back home around three o' clock in the morning. I no longer do things like that. I am going home early to look after myself in the best way possible.

"Small details make the difference. When you get older, you might lose some of your physical abilities, but you get more mature. I live for football, look after myself and train hard.

"There is nothing in life that I enjoy more and my body is incredibly important. That's why I look after myself and that's why I still play at the highest level."

Ronaldo has netted 13 goals in 13 appearances in all competitions for Madrid this campaign.