insomnia
n. uncountablen. a condition where you find it very hard to fall asleep or stay asleep at night. It often leaves you feeling tired and grumpy the next day.
n. the habitual inability to fall or remain asleep, often resulting in daytime impairment or distress. Frequently associated with psychological or physiological factors.
She suffered from insomnia for weeks before seeing a doctor.
Stress at work can often lead to temporary insomnia, making it difficult to focus during the day.
Chronic insomnia may require a combination of cognitive behavioural therapy and lifestyle adjustments to restore a healthy circadian rhythm and improve overall sleep hygiene.
Borrowed from Latin īnsomnia, from Latin in- (“without”) + somnus (“sleep”, noun) + -ia, equivalent to in- + somn- + -ia.
Often follows the verbs 'suffer from' or 'experience'.