Scottish football legend Denis Law has revealed that he has been diagnosed with mixed dementia. 

The former Manchester United player, who made 404 appearences for the club and is considered one of their all-time greatest players, decided to make his diagnosis public while he is still in a position to do so. 

In a statement, the 81-year-old said he "wanted to be open about his condition", which he described as "mixed dementia". 

But what exactly is the disease? Here's what you need to know. 

What is mixed dementia?

Mixed dementia is a condition in the brain which causes more than one type of dementia to occur at once.

On Thursday morning, Denis Law confirmed he had two types of dementia: Alzheimer’s and Vascular dementia. 

This combination is the most common form of mixed dementia, with the disease thought to be much more common than is necessarily diagnosed. 

Often only one type of demenita is diagnosed in a patient, while autopsies frequently show more than one form was actually present. 

As a result, researchers are keen to investigate the disease in greater detail.

Alzheimers is a form of dementia which impacts memory, thinking and behaviour. 

Meanwhile, vascular dementia has similar symptoms but is caused by problems with supply of blood to the brain. 

If the vascular system becomes damaged, this can prevent blood from reaching the brain, which in turn can cause brain cells to die.

The death of brain cells can cause problems with memory, thinking and reasoning, and when these problems have an imoact of everyday life, it is referred to as vascular dementia. 

What has Denis Law said about his diagnosis?

In a statement released on Thursday morning, Denis Law said: "I am at the point where I feel I want to be open about my condition. I have been diagnosed with ‘mixed dementia’, which is more than one type of dementia, in my case this being Alzheimer’s and Vascular dementia.

"This has been an extremely difficult year for everyone, and the long periods of isolation have certainly not helped. It is an incredibly challenging and problematic disease and I have witnessed many friends go through this.

"I am trying to be positive and determined to continue watching my club, Manchester United at Old Trafford, hopefully this will be a season of success and I am excited by the new signings that Ole and the club have made."

His announcement makes him the sixth member of United's European Cup winning squad of 1968 to be diagnosed with dementia. 

In response to Law's statement, Manchester United said: "Denis Law will always be one of this club’s greatest legends and everybody at Manchester United sends our love and best wishes to him and his family. We know our fans around the world will also rally behind him.

"We applaud Denis’s brave words and will continue to offer whatever support we can as he adapts to this challenging condition."