You should avoid caffeine and smoking in the hours before bed and try to keep other activities on a schedule. There is no guarantee the adjustments will make a person rest easy and if problems continue, there may be a sleep disorder. There are dozens of ailments related to sleep, but insomnia, sleep apnea, narcolepsy and snoring are most common. Insomniacs simply have difficulty sleeping, which may mean not being able to fall asleep or waking up early or often. The lack of rest causes sleepiness, anxiety, and irritability during the daytime hours.
Someone suffering from sleep apnea can fall asleep easy enough, but has difficulty breathing.
When that happens, a person wakes up to a lighter stage of sleep, but not completely. The problem can be serious, and has been linked to heart disease, headaches and personality changes. Narcolepsy is also dangerous because it causes a person to become extremely sleepy at random points in the day. In its most severe cases, the disorder can bring havoc to a person's work and relationships. Unlike the others, snoring is a well-known disorder which people generally laugh off.