Medical conditions can be another factor to cause insomnia.
Medical factors can include allergies, asthma, heart disease, high blood pressure, hyperthyroidism and Parkinson’s disease. Pain and discomfort from a medical injury often disturbs the sleep. Sleep apnea is a state where one temporarily stops breathing during sleep. This can be another factor which can lead to lack of sleep. You could also have periodic leg and arm movements during sleep.
Some temporary events or factors can lead to lack of sleep.