The NHS article on insomnia defines it as a condition characterized by regular difficulty in falling or staying asleep, leading to daytime fatigue and irritability. Common causes include stress, anxiety, depression, environmental factors like noise, and lifestyle habits such as alcohol or caffeine consumption. Chronic insomnia can impair cognitive functions, affecting concentration and memory, thereby diminishing overall brain health. To alleviate insomnia, the article recommends maintaining consistent sleep schedules, creating a restful sleeping environment, engaging in relaxation techniques before bed, and limiting stimulants like caffeine and nicotine. These lifestyle modifications are supported by clinical guidelines and aim to enhance sleep quality, which is vital for optimal cognitive performance and mental well-being.