People of all ages can suddenly go blank. They may not remember why they entered a room or where they placed an essential item, such as their house keys. Even worse, the names of familiar people may slip the mind, or a word that was on the tip of the tongue refuse to come out. One may reach a shop and forget what was meant to be purchased, or walk past it in a happy haze. At times, sentences are left half-finished, with words and sequences forgotten.

Occasional lapses like these are not uncommon. They can occur because of lack of sleep or rest, consumption of alcohol or even after a sudden, substantial meal, which seems to divert blood flow from the brain to the stomach. Some medications can also cause such symptoms, particularly antihistamines, cough syrups, muscle relaxants and certain painkillers.

Hormonal changes are another important cause. Thyroid hormones are responsible for keeping almost all organs in the body, especially the brain, functioning efficiently. Thyroid malfunction is often accompanied by other symptoms such as weight gain, dry skin, constipation and fatigue.

In women, the balance between oestrogen and progesterone alters during pregnancy and menopause. At both these times, women may experience memory lapses and mental fog for a few months, which can be worrying but are usually temporary.

By carefully analysing the history, most people can identify the precipitating cause of this temporary phenomenon, particularly if it followed a significant event such as a head injury, illness or substantial emotional stress.

If the symptoms persist, before worrying about psychiatric illness, mental decline, dementia or the early onset of Alzheimer’s disease, specific tests can be done. Blood tests can check for anaemia, thyroid dysfunction and deficiency of B-complex vitamins, especially B12. If the symptoms are severe or progressive, imaging studies such as
a CT scan or MRI of the brain may be advised.

The onset of dementia has a few characteristic warning signs. Memory loss is usually significant, particularly for recent events. There may be difficulty planning future activities or solving even simple problems that require step-by-step thinking. Performing familiar tasks may become challenging. Confusion about dates and times may occur. Some people withdraw socially or develop irritability, anger, anxiety or depression. These changes are often noticed by family members, prompting a medical consultation.

If there is a correctable cause for these, appropriate medication and treatment can reverse or significantly improve the symptoms. Since mental slowing and some degree of “brain fog” are an inevitable part of ageing, it is essential to take steps to safeguard brain health.

Lifestyle diseases such as diabetes, hypertension and abnormal lipid levels should be well controlled. A healthy diet with four to five servings of fruits and vegetables daily is essential. Supplements of Vitamin D3 and calcium may be helpful if a deficiency is proven. Absorption of B-complex vitamins declines with age and medications such as metformin can further reduce it, so supplementation may be advisable. Omega-3 fatty acids may also help.

Physical activity for at least 40 minutes a day releases beneficial chemicals from muscles that improve mental function and increase blood flow to the brain. The brain itself should be kept active through social engagement, reading, puzzles and learning new skills. Adequate sleep of seven to eight hours allows the brain to rest and rejuvenate.

Finally, stress contributes significantly to mental deterioration. Worrying about unchangeable situations does no one any good and should be consciously avoided.

The writer has a family practice at Vellore and is the author of Staying Healthy in Modern India. If you have any questions on health issues, please write to yourhealthgm@yahoo.co.in