A leading dementia expert has revealed ten questions to ask yourself if you believe you may have Alzheimer's disease.

Dementia is Britain's biggest killer, and Alzheimer's Disease accounts for over half—around 60 per cent—of cases. 

Nearly a million people are thought to have the condition, according to figures released by the Alzheimer's Society last year. 

Worryingly, it's estimated that a third of those currently struggling with dementia are undiagnosed.

There has also been a huge spike in the disease being diagnosed in younger people—those aged under 60—whose symptoms are often dismissed as being a midlife crisis.

But what questions should you really be asking yourself if you suspect you're heading towards catastrophic memory loss?

Dr Peter Rabins, a professor of Alzheimer's at John Hopkins University who has studied, written about and cared for people with the illness for 40 years, previously told the Daily Mail that there are ways to tell the difference between dementia and memory loss.

But if you're genuinely worried that you might have the disease, he has also shared ten questions to ask yourself. 

1. Are you struggling to remember the name of close friends or family? 

If you're finding it difficult to recall words or names, Dr Rabins told the Telegraph it can be a normal part of aging.

In a similar way, misplacing where you put your glasses or keys in your 30s or 40s doesn't necessarily mean you have Alzheimer's.

But Dr Rabins said, forgetting the names of relatives, close friends or important events is much more worrying.

For example, he said: 'Let's say you have a doctor's appointment the next day and you've been told twice, or you're attending a wedding on the weekend, which you've spoken about and you don't remember it. That's concerning'.

2. Are you finding it difficult to do things you've previously had no trouble doing?

If you suddenly notice that you're struggling to manage money or cook when you've done so with no problem for decades, Dr Rabins, warns it could be a red flag. 

He said: 'I have seen people who have always cooked the meals and done more of the housekeeping than their spouse for 30 or 40 years, and they'll complain, "I'm getting tired of this."

'But when they're evaluated by myself or one of my colleagues, they have identifiable impairments which go beyond the subtle changes that occur with aging.'

Sadly, he explained the real reason they are suddenly struggling with tasks is because of cognitive decline. 

'Unfortunately it's often only in retrospect people put that together', he explained.

3. Are you struggling with organisational tasks like preparing a meal or hosting?

It isn't necessarily the memory that is first to go, Dr Rabins said, but rather something neurologists call 'executive function', the brain's ability to manage tasks.

'Let's take cooking a meal for example,' he said. 'The person may still remember the ingredients and have an idea of all the steps.

'But when it comes to adding the ingredients in the proper order, remembering to set the table, turn on the stove, and get drinks ready, they can't manage it so well.'

If you've always been a terrible cook or chaotic host, it's probably nothing to worry about, but if it's new or sudden it is worth getting checked out.

4. What medications are you taking?

If you're on certain prescription medications, Dr Rabins said, they can sometimes induce cognitive impairment and confusion.

This is likely due to the drugs and not Alzheimer's if the confusion goes away when the dose is lowered or the drug is stopped entirely.

He explained the medications that have this effect involve anticholinergic activity - the regulation of heart rate, digestion and bladder control.

Therefore, several lung, heart, anxiety and incontinence drugs can cause cognitive impairment in some cases.

5. Can you do things that require multi-tasking?

In clinics where people are tested for Alzheimer's, patients answer math questions, but it isn't to test their arithmetic skills.

Instead, Dr Rabins explained, it's to assess their ability to hold multiple things in their head at once.

'You have to remember the most recent number, the fact that you're removing seven and do the calculation,' he said.

'People will say, "Well I'm going to have trouble with that because I was never very good at maths." 

'And when I encourage them to try, it may be a bit of a struggle, and they need to take their time but they get there.

'If someone really can't do it, that's an indicator that something is happening which is different from ordinary aging.' 

6. How much are you drinking?

In your 70s and 80s, you metabolise alcohol significantly less efficiently than decades before, said Dr Rabins.

This, he explained, can result in foggy-headedness which can be mistaken by people and their loved ones as a sign of Alzheimer's.

The impact of drinking on the body, makes him take alcohol as seriously as a drug 'just like prescription medicines', he said.

Interestingly, he explained, as we get older, the body is far less able to metabolise the alcohol, making us get drunker quicker.

Previously, he explained, 'you might have enjoyed three beers at night and never had a problem with drinking that much.'

But later in life, he said it can be 'too much for your body to handle' which means 'it's really like having six beers rather than three'. 

7. Are you grumpier or easier going than usual?

Experiencing personality changes later in life can be easily dismissed as difficulties adjusting to retirement or accepting the realities of old age.

But Dr Rabins explained it can be a manifestation of changes within the brain due to the illness.

He recalls a successful businesswoman who had always been known for being meticulous with her finances, who suddenly had no interest in it.

'Her relatives just passed that off as it being time for retirement, but when she was tested, she clearly had impairments that were far beyond usual aging,' he said.

Sadly, even if you are noticing positive personality changes, it can still be a sign of Alzheimer's disease.

One patient, he explained, had a troublesome relationship with his family because of his difficult nature but suddenly became more loving and caring.

It was initially welcomed as a positive change - but Dr Rabins explained it turned out to be the beginning of Alzheimer's.

'They actually found it very hard to provide care for him when he needed it, because he'd been so negative and argumentative throughout their childhood and adulthood.' 

8. Do you worry excessively about things you never used to?

If you're excessively worrying about your memory and cognition, Dr Rabins said it can actually be a warning sign of the illness. 

He explained some people experiencing these problems can start subconsciously retreating from the world.

For example, they may decide to not go on holidays or socialise as they fear not being able to cope or being embarrassed of their memory difficulties. 

9. Have your sleeping patterns changed?

Previous studies have shown the relationship between sleep and Alzheimer's is complex. 

They found that disturbed sleep over many years can be an early predictor of the illness. 

This can manifest as being an early riser, sleeping for longer in the morning or needing to take naps in the day, Dr Rabins explained. 

Similarly, he added if you're a deeper sleeper and you've suddenly had changes to your sleeping patterns and don't feel fully rested, it could be a sign of the illness.

10. Do you no longer enjoy activities you used to?

Not enjoying things you used to is a hallmark of depression, but Dr Rabins said it can be a sign of Alzheimer's too. 

He has seen past patients who describe suddenly losing passion for the things they once enjoyed like reading and even spending time with grandchildren.

'They blame themselves for things that they're really not responsible for or they start putting themselves down,' he said.

'I had one older patient who had always regularly played cards with friends, and he began to say, "Well I don't get pleasure from that anymore."

'The family initially attributed that to, "He's just getting older and his friends are dying off," but it was a sign of Alzheimer's.