Five medical issues that can be mistaken for dementia

Depression, thyroid problems and Vitamin B12 deficiency can all cause forgetfulness

Understanding Alzheimer's and Types of Dementia

If you go into a room only to forget what you went in for, you're not alone. Most of us find our memory declines with age, but that doesn't necessarily mean it's a sign of dementia or Alzheimer's disease.

Having said that, if forgetfulness is becoming an issue for you, it's best to see your GP as soon as possible. Even if it's not dementia, forgetfulness can be caused by a number of other medical conditions – and the sooner you're diagnosed, the sooner you can get treatment.

See also: People 'frequently misdiagnosed with common types of dementia'

See also: Eight hidden signs of dementia

1. Depression
According to Age UK, more than 20% of people over the age of 65 suffer with depression, and many of them go undiagnosed.

While tearfulness, lack of interest in life, and tiredness are some of the most common symptoms, depression can also affect your memory and ability to concentrate.

Those suffering with depression may also struggle to remember words – known as delayed verbal recall - and may speak more slowly.

If you're concerned, see your GP who may be able to prescribe a course of antidepressants. Exercising, especially in the outdoors, relaxation therapies, eating healthily and spending more time with friends and family can also make a positive difference to your mental health.

2. Underactive or overactive thyroid
Both an overproduction of thyroid hormones (hyperthyroidism) and underproduction (hypothyroidism) can cause dementia-like symptoms.

An underactive thyroid (hypothyroidism) is more common in women and is believed to affect one-in-five people over the age of sixty. Symptoms tend to develop slowly over several years and are similar to a number of other conditions, so may be confused for something else.

Signs can include memory problems, slow movements and thoughts, depression and tiredness. Other symptoms, which distinguish it from dementia, include sensitivity to the cold, weight gain, constipation, muscle aches and weakness, dry skin and brittle nails, a numbness and tingling sensation in the hand, loss of libido and irregular or heavy periods.

See your GP who will be able to run a blood test. Most people find that medication improves their symptoms within a few weeks.

3. Urinary tract infection
Urinary tract infections (UTIs) are very common, and tend to affect more women than men. It's estimated that half of all women in the UK will have a UTI at least once in their life, and 1 in 2,000 healthy men will develop one each year.

If you've ever had one, you'll know how unpleasant it can be. Symptoms include pain and a burning sensation when urinating and feeling the need to pee more often. Some people may also become feverish and experience more frightening symptoms, including hallucinations and delirium.

Older people are more susceptible to dehydration, which can be caused by UTIs. Symptoms may include a lack of awareness of surroundings, problems following a conversation or speaking clearly, vivid dreams or nightmares, hallucinations, slowness, mood changes, restlessness and wandering.

Unlike dementia, the symptoms come on quickly in a matter of hours or days instead of developing slowly over several years.

If you notice cloudy, unpleasant-smelling urine and have a general feeling of being unwell, see your GP who can prescribe a course of antibiotics. Make sure to stay well hydrated.

4. Vitamin B12 deficiency
Vitamin B12 or folate deficiency anaemia can cause a wide range of symptoms, including problems with memory, understanding and judgement.

Symptoms usually develop gradually at first, and worsen if the condition goes untreated. Other signs include extreme fatigue, pins and needles, a sore and red tongue, mouth ulcers, muscle weakness, irritability, and depression. If you have anaemia caused by a vitamin B12 deficiency, you may also notice a pale yellow tinge to your skin and disturbed vision.

While diet can be the cause for some people, a B12 deficiency can also be the result of a condition affecting the stomach, or taking certain medications, such as proton pump inhibitors – a medication sometimes used to treat indigestion.

See your GP, who can run a simple blood test. If you're concerned, taking a supplement may help. Researchers in Oxford found that taking a combination of vitamin B12 (0.5mg/day), plus folic acid (0.8mg/day) and vitamin B6 (20mg/day) for two years significantly slowed brain shrinkage in those with mild cognitive decline.

5. Your medication
Getting older can often mean taking more medication, and combining different types of drugs can increase the risk of suffering from dementia-like side effects.

The following medications can all cause dementia-like symptoms: Anticholinergics (prescribed to treat asthma), antidepressants, antihistamines, anti-anxiety medications, anti-Parkinson drugs, cardiovascular drugs, anticonvulsants, corticosteroids, sedatives and drugs used to treat insomnia.

In addition, medication used to treat incontinence, gastrointestinal problems, muscle spasms and high blood pressure can also cause confusion, while opiate painkillers, for conditions such as arthritis and back pain, can diminish alertness.

If you're concerned, see your GP - it's a good idea to make sure your medications are regularly reviewed. Never stop taking prescription drugs without speaking to your doctor.